Consider: Jon having sex purely for time management purposes.

He has no drive to sleep with other people, but ever since he started testosterone his body has demanded daily orgasms. Sleeping with other people is more satisfying than handling it himself and has actually helped to tame it a bit, so overall he spends much less time masturbating than previously. It’s nice, because it means he can go home satiated and watch some documentaries instead of spending an hour furiously wanking until his body is done making its demands.

He’s not too interested in reciprocation, although he doesn’t really mind it either. Mostly he wants an in and out ten minute encounter that will help him feel more grounded, and if his partner also gets off during that time then good for them.