Both girls nodded, as they had known Alex's body condition since they were children.
"So, since Alex has both genders, he has two sets of sexual organs. The one that we girls have is called a vagina."
The other two girls were seemingly intrigued by Katherine's explanation, but Alex's brain was in a completely different dimension.
It just felt extremely awkward for him to watch his sibling learn about his body right in front of his mom.
More importantly, he already has this kind of knowledge and just felt embarrassed to be different from everyone.
"And the other sexual organs he has is called a penis... It's the thing that usually only men have."
As Katherine calmly explained it to the three, Sophia's face started to blush a little, as she already knew a little bit about it.
"You two probably had seen it endless times already. Your brother's penis is the thing that's sticking out."
"Where's brother's vagina?" Mary curiously asked.
"It's just right below his testicle... If you guys really doubt he has one, remember he has period just like Sophia."
Katherine took a little pause before looking back at the three kids, examining the emotion on their faces.
Alex was more embarrassed than ever, as she expected.
Meanwhile, Sophia blushed a little but still listened to her explanation, Mary being the only one who didn't seem to be affected at all.
Instead, her face was full of questions, clearly wanting to know more about this kind of stuff.
"Now I'm going to explain first about how the penis works... You two had probably seen Alex getting hard, right?"
Both girls nodded in agreement.
"Usually, a penis only gets hard when they see something that turns them on."
"What's turning the... penis hard exactly?" Sophia quietly asked.
"It can be anything. It can just be a simple touch or seeing a girl naked, or it can just be something attractive."
"Did brother get hard because they saw our naked body?" Mary curiously asked.
"No, I——"
"It's okay, Alex... We know you didn't get hard because of looking at our naked bodies.
As I said, it can be anything... Especially when they are still young, sometimes their body just has their penis erect at random times.
It's out of their control. So don't blame or shame your brother when that happens, okay?"
Seeing both girls nodding in agreement, Alex felt a little guilty.
He knew what Katherine said was partially true, but the reality was that he got hard after seeing naked bodies.
"Now we finished talking about Alex's body——"
"Mom, you still haven't answered the thing that came out of Alex's body." Sophia quietly pointed out.
"Um, when someone rubs or presses onto an erect penis, it can cause it to ejaculate the white stuff that you two saw.
It's called cum, or specifically semen... The purpose of it is to make a baby when it mixes with a girl's ovum."
"Ovum?"
Both Sophia and Mary looked a little confused, and Alex looked slightly confused as well.
Both girls nodded in agreement as Katherine turned her attention over to Alex.
"Mom, I——"
"It's okay, Alex... Dad should be here talking to you about that stuff, but I can explain it to you."
Alex wanted to tell Katherine he already knew, but he just couldn't muster the courage to do so.
"So how a boy can masturbate is very similar, but rather than playing with the clitoris, they gently stroke your penis with their hands.
It's a simple up-and-down motion... But be careful. You don't want to pull your foreskin too hard back.
Your body might not be fully developed enough for it to peel all the way back, so just keep that in mind when you play with it."
Alex silently nodded his head, his face blushing red as he listened to Katherine's explanation.
"So that's it. That's pretty much all I have to teach you guys. Oh, right. During puberty, your body starts developing hair all over.
But it's completely normal, so don't worry about it. You guys probably had seen the hair on my body, right?"
Both girls nodded in agreement, with Alex's mind thinking back to Katherine's mature body.
"I can't wait for puberty!" Mary excitedly declared.
"You're not going to say that when period hits you," Katherine replied as she gently patted her head.
"Mom, how come you don't seem to be affected by periods at all?" Sophia suddenly asked.
Katherine fell into silence for a second before speaking up.
"It's magic... It will make you super short and ugly if you use it when your body isn't fully developed."
All three of them instantly fell into silence, not asking her on how to use that spell.
"Okay, you guys go to bed now——"
"Wait, wait. We still have homework for today," Mary quickly pointed out, with Sophia about to say the same thing.
"Oh really? What homework is it?"
"We still have to meditate tonight. Miss Amelia just taught us how to do it today." Sophia replied this time.
"That's good. How long did you guys mediate for?"
"We both meditate for about an hour," Sophia replied as she grabbed Mary closer.
"That's amazing for the first time... Alex, how about you?" Katherine asked, noticing him to be silent the whole time.
"I... I did very badly. I'm sorry, Mom. I disappointed——"
Before Alex could finish talking, Katherine suddenly gave him a warm hug.
"There's no need to apologize, okay? You didn't disappoint me. You're always going to be my son, no matter what."
Seeing the two hugging each other, Sophia and Mary stepped up as well, surrounding Alex in a group hug.
"You're always going to be our brother, too!" Mary excitedly stated.
"Yeah, and I'm sure you'll be a great mage in the future, too," Sophia added.
"Thank you..."
As the four hugged each other in silence, Alex held in his tears, feeling grateful to the three.