As I have posted in another thread, age play and med fet work together nicely for my wife and me.
Visualizing her as a physically mature but naive young woman going to an older male doctor for her first adult physical exam is very erotic to me. Of course, the doctor takes advantage of her naïveté and shyness and, though things are kept realistic and believable, he oversteps the bounds of propriety for his own pleasure. The exam is longer than necessary, she is exposed more than necessary and asked unnecessary intimate questions. The doctor takes pleasure in observing her humiliation and involuntary sexual arousal.
The same scenario turned around, with me as the physically mature but naive young man going to an older female doctor for similar abuse, works equally well for both of us. The attractive older woman doctor explains to me that, this being my first exam since puberty, she will be doing a reproductive system and sexual function assessment, which will require her to stimulate an erection and ejaculation.
Often we do not actually role play, but she indulges me by fantasizing one of the above scenarios while she masturbates me. Try as I might, I never get through the whole exam without a powerful orgasm and ejaculation. Of course, if it looks like I might not come before the end of the story, my wife cheats to make sure I do. When, as she is getting to the rectal exam, in either version of the fantasy, she slides her long, slippery finger up my ass and stimulates my prostate, it quickly causes me to have an uncontrollable climax.