Both brother and sister ran breathlessly to the supply closet when the fourth period ended. Katherine ran with her hands on the front and back of her groin region, ensuring that her very short skirt didn't fly up as she ran, since her skirt only extended about two inches below her pussy.
They ducked into the supply closet as soon as the coast was clear.
Katherine immediately saw why Alan had chosen it. It was like a narrow hallway, and it had a door to a smaller, inner supply closet at the back.
They went into that room and turned on the light. There was so much stuff everywhere that there wasn't much room for two people, but they managed. They used the back room so that someone could still open the first door from the hallway and perhaps not realize that people were in the inner closet.
"Turn around, pull up your skirt, and pin it to your sides with your arms," said Alan in a commanding whisper. "You're going to have to stay in that position for a while."
He squatted only inches from his sister's butt. "We'll do the ass first, 'cos it should be easier. It'll be faster and less tiring if you kneel and bend over so you don't have to hold the skirt up."
Katherine got on all fours and bent down, with her head near the floor, allowing him not only to study her butt in great detail but also to examine every intimate nook and cranny of her pussy despite having only an overhead light source.
The sight took his breath away. In fact, the only pussy he'd been able to examine closely so far was Suzanne's, and even then he'd had limited access. Now he could take more time and even touch it as much as he wanted.
He leaned forward until his face was just inches from her ass. He inhaled deeply the scent of her ass and pussy. That made his erection strain so much against his shorts that it took all his willpower not to lean forward and lick her puckered anus.
Finally, he continued, "Here, show me with your hands exactly where the edges of your underpants go."
She reached behind and drew two lines with her hands. They were exactly the same as the tan lines from her bathing suit, which made his job easy.
Alan was actually amazed at just how revealing the cheerleader outfits were, considering that they were for high-school teenagers.
He immediately began painting and tried to imagine he was just painting a statue. He thought the task might take the whole lunch period, which would leave no time for it to dry. "This is a special fast-drying latex paint. You're lucky I'm taking art this semester so I have access to these supplies. Because it's latex, it won't damage your skin like an oil paint, and, like exterior house paint, once it dries it won't smear or come off if it gets wet with sweat or whatever."
"When I think about your face only inches from my butt, I'm afraid there might be a lot of leakage of 'whatever' before too long," Katherine giggled.
"Come on!" he urged. "Let's get serious here. There's no time to play around."
"Does that mean you'll play around with me later, when we have more time?" she teased.
He chided, "Don't tease or you'll leave here with just half a black butt!"
He sped on, but he was actually pleasantly surprised at how fast the painting went. Within three minutes, he had pretty much painted her whole ass. He mostly used a wide brush, but switched to a narrow brush for the edges.
"I'm almost done with the back," he proudly announced.
"I think you need to pay more attention to the crack," she said seductively. "And I would rather you stick something thicker in there than that skinny little stick you're using. I know just the thing, and you have it in your shorts," she giggled.
He laughed too, but was disturbed and nervous. Would she really want me to fuck her? Especially after Mom's new attitude? "Sis, I'm shocked! You never used to talk like that before."
"Well, I've never had my brother paint my butt before!"
They both laughed again. Despite himself, Alan found that he was getting over the morose feeling that he'd had that morning because of his recent tribulations with his mother.
"Shhhh! No more jokes; we have to keep it down. People use this closet sometimes, you know." He dropped his voice to a near whisper. "And also, since we're doing this in kind of a public place, it's probably prudent that you call me something other than 'Brother.'" His voice returned to its normal volume. "Okay, now we have to do the front."
"Oh goody, B.B.! The act we've all been waiting for!" she giggled. She'd never called him 'B.B.' before, which was obviously short for 'Big Brother', but that was the first thing to come to mind since he didn't want her to say anything that showed they were siblings.
"Come on, Kat; you're making this very hard." He didn't call her 'Kat' much except when Amy was there with them too, but he forced himself to use it now so he wouldn't say 'Sis' while engaging in such a compromising act in school.
"There are other parts of you I'd rather make hard. Maybe next time I can paint YOUR privates? I know what part I'd like to spend a long time on! Then afterwards we can test if the paint's dry enough by sticking it in a certain wet hole."
"Kat, do you realize what you're saying?! Do you really mean that?" He wasn't really sure what he wanted when it came to that. As much as he was attracted to her, she was his sister, so this was a huge, irreversible, step to take.
"Sorry, Bro. Er, I mean B.B. It's just that, especially since Mom and Aunt Suzy turned all fuddy-duddy, I thought a little teasing could do you a world of good."
He rolled his eyes, obviously annoyed at her use of terms like 'Mom'. He hoped his expression made clear that he didn't want her to use that word either. "Thanks, I guess, but we're losing precious time. I'll put the brushes down and hold up your skirt while you draw the cut of your panties in the front. You'll have to stand up for this part."
She quickly stood and indicated the area to be painted. It covered the entire V-shaped area between her legs and a little more than her tan lines.
He painted as fast as he could, going right to the edge of her bush. Again, he traced the outlines first with a small brush, and then quickly filled in the rest with a larger one.
"I may have to get a little paint on the edge of your bush," he said as he got near to finishing all but her most private region. He actually painted over her pubic hair along all the edges.
"That's okay; you can do anything with my bush that you like."
"Kat! Don't talk like that!"
"But it's so fun! It's just teasing."
"I think this new Kat is dangerous."
"I'm only like this with you."
"Dangerous for me then. In any case, I think I'm finished painting. Why don't you step back so I can see how it looks at a distance?"
She stepped back, and then whispered in a little girl's voice, "Oh no, old man, don't look at my cute little virgin pussy! The wind has blown my skirt up and I can't get it back down! Whatever will I do?"
"Very funny. Ha-ha." He tried to sound sarcastic and annoyed, but he still had a raging erection in his shorts. "Sorry, little girl, but I'm afraid there's one problem. It's possible to see your pussy lips. Especially if you get excited like you are now, your pink pussy lips will stand out from a mile away."
"Uh-oh," she said, now in her normal voice. "Does that mean the whole thing won't work?"
"Well, I could try painting them too, I guess, but I don't know if the paint will stay on."
"Oh goody!" she said again in her little girl's voice. "Now the dirty old man is going to touch my pussy!"
"Only with my paintbrush, you evil little girl. And before you start making lewd comments about my paintbrush and the size thereof, may I remind you that if you get wet down there I can't paint. So think and say nothing but wholesome thoughts. Better yet, don't say anything at all, 'cos I have the feeling that anything you say today is going to come out horny."
She giggled. "All right, I'll think completely wholesome thoughts about your dick. And wholesome thoughts about how you're going to stick it in my hole some."
Alan couldn't help but laugh at her 'hole some' pun, and laughed even more than usual to relieve his tension. But he said, "Okay, that's it. Don't talk at all, period. I'm serious."
Using the detail brush, he painted her labia. They actually were already fairly wet. He tried to dry them off as best he could with the back of his hand, and then painted some more.
Katherine, meanwhile, actually did her best to keep her mouth shut.
To his surprise, the paint stuck even there, on parts of her labia that were normally hidden from sight. It was really the perfect paint to use, he reflected.
"All right. You're lucky," he finally said. "This paint is so amazing, I could probably paint Jell-O with it. Now all we have to do is wait for it to dry."
"Thanks a lot, B.B. Can I talk now?"
"No! Not unless it's completely nonsexual."
"Then I have nothing to say," she teased.
Five minutes went by. Katherine continued to stand there with her skirt bunched up around her waist, completely exposing what was below. From a distance, now it really looked like she wore black panties. Alan had even drawn on the sides of her hips to imitate the little stretches of cloth which connected the front of her panties to the back.
The only jarring thing that really gave away the paint job was her pussy hair. Luckily, it was very closely trimmed. Without the hair, Alan was sure the paint job could fool anyone at a distance, given that the whole area was usually under a skirt, making it likely that she'd flash the crowd only briefly and occasionally. The only likely problem would be if someone nearby like the other cheerleaders got a good view from a few feet away.
Another five minutes went by. He'd finished the painting about ten minutes after the beginning of the lunch period, and the paint had dried for another ten minutes. Her skirt kept slipping lower, but it didn't really matter - he touched the paint and noticed that it was already almost dry.
They had another twenty minutes before the forty-minute lunch period was over. The paint job looked pretty good. The only problem was some lightness in the pussy-lip area and the fact that her bush stood out a bit. But overall it was hard to tell that anything was amiss.
He finally spoke up. "You know, if I'd known we had this much time, I would have tried to find some way to shave off all your pussy hair. Then it would be completely convincing."
"Don't worry," she replied. "We can do that next time."
"Next time? What are you talking about? There won't be a next time!"
"Don't get your panties in a bunch," she chided.
"If I had panties to get in a bunch, I'd give them to you-"
"And then we wouldn't have to do this." She finished his sentence. "I know."
"Hey, do you have a bag lunch in your backpack?" he asked.
"I do," she answered.
"We still have about twenty minutes to eat lunch, so why don't we share it?"
They did. He held up her skirt while she ate her half of a sandwich. They chatted about things at home.
"You know, B.B.," Katherine said, suddenly changing the subject, "This room is really perfect. Not just for painting people's privates, but for doing other things with those privates as well. I'm surprised people don't come in here to make out or have sex. Or do they?"
"They don't, 'cos you have to be a teacher's pet like me to be able to get a key to come in here in the first place. Didn't you notice that when I unlocked the door?"
"Who did you get it from? No, wait, let me guess. Ms. Rhymer."
"Good guess."
"I have a really nasty thought."
"Those are the only thoughts you're having today!"
"Yeah, well, this is a really erotic experience. Do you know how sexy it is to imagine the hundreds of people in the stands today who will be looking at my completely naked pussy? At any time someone might realize I'm not wearing panties at all, and then they'll tell the next person, and soon the entire crowd will know. And then everyone will forget about the game, and stare only at me. Maybe they'll all decide that-"
"Whoa, whoa, there!" he interrupted. "Before you get too carried away in your slutty little fantasy, remember that the paint is still drying."
"All right, party-pooper. Anyway, it's good to keep the lips engorged a bit. Trust me, it's really erotic. I wonder how I'm going to stop from leaking like a broken faucet. Everyone will realize what's up when they see all the liquid pouring down my legs, and then I'll-"
"Time for a change of subject!" he interrupted again. "I'm afraid to ask, but what's this nasty thought of yours that you were going to say earlier?"
"Oh yeah, that. What if you don't return the key to Ms. Rhymer? Just say you forgot. I know a place that'll make a copy of any key, and then return it on Monday. And then you or I, or you AND I, could come in here anytime and do whatever we want!"
"I'm not even gonna go there and ask what we'd be doing in here," he said. "Don't you know how much trouble I could get in for doing that with the key? Especially with Ms. Rhymer. She'd never forgive me for breaking her trust, and I really like her; I don't want her mad at me."
"Well, if she's so mad at you, maybe she could take you in here and give you a proper spanking. Wouldn't you like that? And then when she's done spanking you, then I could think of some things she and I could do to your sore, red butt that would make it feel all better again," Katherine giggled.
"Kat. Really! Get a grip on reality. Anyways, it's not like that between her and me. I don't think of her that way. She's just a, uh, mentor-type figure."
"Yeah, right! I know what subject you'd like her to 'mentor' you in, and it isn't history. Come on; she's hot - even I might consider doing her. Everyone at home knows how you feel about her, so don't deny it."
He just had an "Aw, shucks," expression as he stared at his feet.
Changing the topic slightly, Katherine added, "You know what? This would be a great room for you to use with Christine as well. Lure her here on some nerdy pretext, and then whip out that impressive dick of yours and say, 'Worship THIS, baby!'"
"Sis, have you completely lost your mind? Do I look like the kind of guy who'd say 'Worship this, baby' in a million years? And if I did, the only question is which karate move she'd use on me first! Anyway, she's not interested in me at all."
Katherine kidded, "So you like the idea of doing the nasty with her in here; you just don't want to use that phrase?"
But he replied, "You're kinda freaking me out. It seems like you're thinking really, really unwholesome thoughts about me. You know about Mom's rules. That's just not right."
"Sorry, but you don't know how erotic this all is. I mean, you've been staring at my pussy for a good half hour now. I suppose you're just 'checking out the paint job.'" She said the latter part in a mock serious tone. She would have made quote marks in the air if her hands hadn't been holding up her skirt.
He didn't have anything to say to that, because he'd been busy checking out and memorizing every detail of her pussy the entire time.