Yes she does

"Sure,” she answers, “what do you have in mind?" she asks as she lays on the bed. “Well I could think of a few things,” you say and gently caress your girlfriend's cheeks , “now that I know that you're partly an animal, I think you need a little training and a collar. Otherwise the animal catchers could lock you up in a tiny cage. You don't want that, do you?”

“No, I don't want them to take me away from you,” Jenny says leaning into your hand and looking at you with puppy eyes, “What do we do to avoid that?”

“Well first you need to learn correct behavior among humans. ” you explain, “Pets don't get to sleep on the bed. Good pets belong on the floor.”

“I didn't expected you to be into such things,” Jenny mumbles and goes on all fours, “but you can be my owner, I love you and I'll be a good pet for you.”

“Aww, you're such a cute little puppy” you say patting her. “However, pets don't use human language.” You say, shoving her face into your pants. This time Jenny barks and pants as an answer licking your crotch, leaving a damp spot on your pants.

“That's better,” you say pleased and caress Jenny's head, “I see you are willing to learn. Today we'll go easy on you but in the next lessons we'll see how well you lean your tricks. For now frolic around a bit! Try to catch your own tail! Do what dogs normally like to do!” you take off her pajamas halfway to expose her ass.

Jenny barks happy and crawls around, hips swaying as she gives you a show. She acts like she she's chasing an imaginary tail. You look away after a while and she bites your pant leg and pulls on it so you stand up and play with her.

“Bad dog, let go.” you reply and slap Jenny's ass, “How do good dogs ask for things?". Jenny hisses but then looks to the ground and whimpers, begging. She looks so cute you reach out, scratch her back and embrace her. You finger her pussy to find it nice and wet. She whimpers some more and you push your finger deeper, feeling the heat inside.

Licking your fingers with one hand, you take off your pants with the other. You sit back on the bed, legs wide open, inviting her to enjoy herself. She takes her place on the floor, facing away from you with her ass in the air. You hold her in place as she's about to move. "And what do good pets say before they get their reward? also you may speak." you instruct her. "Thank you masterrr" she answers desperately as she begins to hump the tip of your cock. You let her go and she falls backwards on your erection.

"Good girl" you say as you reach out and grab her hips. You kiss her neck, fondling her perky ass. You feel her legs tremble as pound into her from behind.

"Aah" Jenny moans as she tries to reach the spot inside her. "Master harder" she moans as you begin to continue to fuck her from behind. She bounces on your dick wildly trying to get more stimulation as she feels her orgasm building, Jenny closes her eyes and lets her face turn to a complete ahegao, tongue hanging out as she drools.

You grab her butt and hilt yourself inside her as forcefully as you can. She moans out in pleasure as you cum into her, her body shaking as her oncoming orgasm slowly... fizzles out? She is confused and shivering as to why she's no longer in a frenzy of pleasure. You hold her, her eyes closed and shivering as you both come down from your sexual highs.

You cuddle for a while, before you both need to get cleaned up. You courteously let her take the shower first first, temporarily cleaning up your the mess with tissues, making sure nothing drips on the bed.

(Jenny's view)

Jenny walks into the bathroom and heads straight for the hand shower. "Fuck I need to cum, please please pl..ah" she stifles her moans as she aims the water jet at her unsatisfied pussy. She lets the water flow over her clit, bringing her back to a state of sexual ecstasy. "Finally" she thinks as she presses down on the shower head. She bites her lips as she finally cums, her juices mixed with water splashing all over the shower floor.

(Back to normal)

Once you're both cleaned up you hang out together in her room for a while before leaving. “Well, then let's meet tomorrow before class,” you say after you give your girlfriend a goodbye kiss, “oh yeah, one last question. I still haven't decided on a collar for you. What do you think about a pink one?”

Instead of an answer Jenny points her tongue out and closes the door, blushing. You get back in your own room and try to rest a bit.

I hope I managed to deliver on the sex scene, particularly on the submissive and unsatisfied aspects.
The planned next few chapters will continue along the main branch starting at "Tomorrow is school" with little to no effective changes, but feel free to add any ideas that you want included.