After just a minute of touching themselves, all three of them were on the edge of climax.
Their finger were soaking wet as their body kept on producing more lubricant every time they gently touched the clitoris.
"When it's lubricated enough, you could slowly insert a finger inside... But be careful, your hymen is located here.
This is sometimes how people determine if you had sex before... It should be fine to put your finger inside as long as you don't force it.
Remember, it's not the end of the world if it breaks. It usually slowly tears itself as you grow older, so it's sometimes out of your control——Hm!"
As Katherine slowly inserted her finger inside the vagina, she bent it a little before letting out a seductive moan.
"Everyone is different, but there's a sweet spot that you want to touch——Ah!"
Her increasingly seductive moans immediately made all three blush again as they slowly tried to insert their finger inside their own vagina.
Within seconds, all three of them find their sweet spot as they all let out a high-pitched moan at the same time.
"In the future, you can also play with your boobs and nipples, but for now, just focus on your sweet spot and the clitoris——Hm!"
All three of them didn't say anything back, but their moaning sounds were starting to blend together.
Soon, Sophia and Mary could feel something coming out.
"Mom, w-why does it feel weird——Hm!" Sophia nervously asked, trying to hold in her embarrassing moan as she couldn't think straight anymore.
"You're reaching orgasm, or climax. This is when you finally reach your body's limit——"
"Ah!"
Mary was the first to climax as a very small bit of clear liquid flew straight out of her vagina, with her legs shaking a little.
"M-Mom? D-Did I p-peed the bed?"
Mary shyly asked as she looked a little embarrassed at the wet stain she had made on the bed sheet.
"No, sweetie. It's just a woman's squirt, similar to your brother's semen... It can sometimes be released when you really enjoyed how well it went——"
"Ah!"
Before Katherine could finish talking, Sophia started climaxing, shooting out a clear liquid as she tightly clenched her legs together.
"Both of you really inherited it from me... Don't worry about the mess, just relax, okay?"
As she gently helped the two of them lean back down onto the bed, Alex was having a completely different story.
He was constantly on the verge of climax, but his cock was painfully erect to the point that it was starting to hurt for the first time.
Every touch with his clitoris made him want to ejaculate, yet the lack of touch on his cock prevented anything from coming out.
Unable to endure it any longer, he slowly reached his other hand down, gently holding onto his cock.
"Alex..."
Katherine's voice instantly caught both of the girls' attention as they sneakily sat back up behind her to watch their brother.
"M-Mom I-I'm sorry, I can't stop——"
"It's fine, Alex. There's nothing wrong with you masturbating with your penis... Can you not climax through your vagina, though?"
"I-I don't know——Ah!——Mom, I'm cumming!"
Two short bursts of liquid, one white from above and one clear down below, flew straight out of Alex's genitals.
Feeling something hot on her legs, Katherine looked down and noticed some of the white stains had landed on her thighs.
A weird feeling began to develop inside her mind, but she quickly dismissed the thought as she started chanting in her breath.
Within seconds, the stain on her body immediately evaporated into the air, but a small amount remained on her thighs.
"Brother is just like us..." Sophia murmured as she noticed the clear liquid coming down from his labia.
"So that's how a boy masturbates. So weird..." Mary murmured as she watched the penis soften back down.
"Ahem, Alex, who told you to cum on your mother's leg?"
Katherine questioned as her attempt to wipe the remaining semen off was now stuck onto her finger.
"Sorry... I-I didn't know it could do that."
Seeing him genuinely looking ashamed, Katherine's heart softened after realizing he was still just a kid who couldn't possibly know better.
"Don't do that again... Ahem, now you three know how to masturbate. Here's a helpful magic trick to get rid of all the mess."
All three of them waited in silence as Katherine held her hands together before chanting a line out loud.
"May the goddess of Water clean your souls."
As Katherine chanted the line again and again, the stains on the bed quickly evaporated into the air.
"Just think with your mana and chant the line... There's no need to re-arrange any element or ratio for this spell."
All three of them closed their eyes and focused as they tried to chant the same line as her, which surprisingly worked.
They could feel the stains they had made on their body starting to vanish, almost as if they were never there.
"You three can go back to your room to sleep now... Remember, only do this kind of stuff in private, not in front of each other.
It's strictly forbidden for siblings and parents to do this kind of stuff, okay? I only did this once to teach you three to do it yourself in the future."
The three of them nodded in agreement as they put on their underwear and pants before getting ready to head back to their room.
"Wait, Mom. We didn't get to see you reach climax——"
"It's already way past your bedtime. Go back to your room before I tickle your belly again."
Katherine quickly shoved the three of them back into their bedroom, her face blushing red as she couldn't believe Sophia's request.
---
A few minutes later...
"Fuck. Why did I do this in front of them? What's wrong with me?" Katherine murmured as she lay back down on the bed.
With a snap of the finger, the light in the room turned off, and the door closed as she shot a light beam at it.
"No normal mother would ever teach their kids this kind of stuff with their own body... But I'm a single mother, right?
Who else is going to teach them about sex-ed? The school doesn't cover that kind of stuff at all..."
Katherine's mind started to look for excuses, as she felt ashamed for how weird she had been behaving in front of the kids recently.
More importantly, she still couldn't believe she was turned on by her own son's cum landing on top of her legs.
"Come on, you idiot. They are your kids. Stop being a perverted mom. You're just teaching them sex-ed and nothing else.
It's nothing to be ashamed of. Mom taught me this, too... It's only going to be a one-time thing... Only a one-time thing."
As Katherine slowly justified her action, her mind was starting to feel twisted all over the place.
"It's never going to happen again, right? This shouldn't turn me on... But why am I getting wet just from thinking about this?
Is it because I didn't cum earlier? Why does it feel more exciting to do it in front of them? What's wrong with me?"
After thinking for a bit, Katherine threw everything out of her mind, shifting her attention back to falling asleep.
"I can't betray Paul..."
---
Meanwhile, back in the kids' bedroom.
"Alex... Was that what men's cum looked like?" Sophia curiously asked as the three of them lay down on the same bed.
"Maybe..."
Alex didn't elaborate any further as his mind still couldn't believe his body managed to squirt and cum at the same time.
"So that's what Mom said can make a woman pregnant," Sophia murmured to herself as she turned to the side.
As the room fell into silence, Alex's mind started to wish to sleep in a separate room from the two.
It was just becoming increasingly awkward for him, especially since Sophia was on his left while Mary was on his right.
"Mom and Dad must have had sex together to give birth to us, right?" Mary suddenly asked.
"Obviously. Or else we wouldn't be here. They had to put his penis and shoot semen into her vagina." Sophia answered.
With the room returning to silence, the awkwardness disappeared as both girls soon fell asleep.
However, before Alex would fall asleep, he could feel somebody's arm resting on top of his chest.
"Sophia's sleep posture is so annoying..." Alex thought to himself as he turned to the side to push it away.
Once again, her arms wrapped around his chest. If it weren't for hearing her steady breathing pattern, he would have thought she was doing this on purpose.
Alex tried his best to ignore it while trying to sleep. Yet, he was hit with another challenge when Mary suddenly scooched back a little.
With Sophia's body pressing him from the back and Mary's body pressing him from the front, his mind was starting to go all over the place once again.
"Calm down. They are your sisters. Don't think of anything weird, and just go to sleep... I can do this..."
After hypnotizing himself for a bit, he eventually fell asleep on the bed as his body was way too exhausted for anything actually to happen.