By "chance" it's peridot

I give the coin a little toss into the air and watch it spin and stop landing flat a little heavy in my hand. "Tails. Lucky pick peridot." You tell her. Ugh. Fine but don't me to be taking notes." Lapis says as she takes a seat getting comfortable. I can Lapis is upset at her loss but does still give a stare at slowly erecting penis.

"Ok for this demonstration Peridot I'm gonna ask you to remove all your clothing from the neck down." She does so almost nonchalantly no hint of resistance or added excitement. She begins by shaking off her lab coat carefully handing it off to Lapis who drops it next to her. Peridot proceeds to remove her tight top and leggings showing her lingers legs and improved set of tits covered in nothing but her simple triangular almost bikini like underwear. It lacked design but was fitting in a way, a dark green triangle with black edges and straps.

She reaches behind her buts stops, "Question! Your penis seems to be enlarging, for what purpose are you shape shifting and do all human possess this ability?" She blurts out seeming a little hot and bothered but genuinely curious while Lapis appeared to be just the latter. "Save all questions for after the demonstration please." I say this out of eagerness to begin.

She finishes removing her clothing leaving her in nothing but her fake glasses adding to her look. "Now as you can see my Penis has become bigger." I tell as Peridot comes closer to inspect then suddenly she grabs it making me quiet. "It appears to have also changed in density she starts moving it around getting a look at it from different angles effectively getting a small moan out of me. "Hm?" She stops to look up. I cough and continue "As I was saying although while these serve multiple purposes it's main objective is procreation. The process is what I will be demonstrating." I then offer my hand to Peridot and pull her back up.

I ask her to go to the table and put her hands on the surface, stick her butt out, and lean forward. She does so perfectly giving Lapis a sideview of the show we're gonna give. I then walk behind her " Now before begin the next step I am going to need to prepare peridot for the next stage." I reach around and grab hold of Peridot's left tit playing with it and lower the other to begin rubbing the entrance of her pussy. I glance back to Lapis closely watching my hands work and rubbing her legs together. "Ok now Peridot I'm gonna go a little further ok?" I update her. "Yeeessshh...uuugh please do go on." I then start to insert my fingers pushing them in then out.

I reach over and put my hand on Peridots chin turning her to almost face me and I begin to kiss her. "Hey! What are you doing?" This shout coming from the up until now quiet Lapis. Now standing separating our lips. "Why are you kissing her!" Confused I look back at Peri who has a face of surprise yet longing. I quickly then realize that from the show while these two Gems lack knowledge of the concept of sex they do know of love and kissing as being apart of it. "It's fine Lapis it's just for the experiment." Peridot reasons. Seeing why she now got a little protective I explain, "I need to properly stimulate my current partner's senses so that I can properly demonstrate the actions I will take in the next stage." "Well...you two can't just kiss each other just for the sake of a demonstration, you just met."