This is a quality of trans embodiment and trans sexual practice that I would have found beneficial to have de-mystified for me, so - something I wish more people were aware of is that it is very, very common for trans people who were afab to be more inclined towards vaginal penetration after being on testosterone. More arousal concentrated there, more craving for stimulation there, and more pleasure and more ease in orgasming from that kind of stimulation.
This is not universal by any means, but it is extraordinarily common. I've experienced this and know others who have; I brought it up at a medical appointment and the NP I was seeing immediately cut in and said "oh yeah, that's very common. I talk to a lot of people about this and it's very common."; if you search on r/ftm you can easily find other people attesting to this experience. Even people who previously hated the idea of vaginal penetration or PIV sex, who found it either dysphoric or physically uncomfortable, can be found saying "oh my god, I love it so much now, it's crazy."
I haven't done much digging into why this happens, though I suspect it's a result of bottom growth extending internally as well, as well as prostate tissue growth. But while I do see a lot of acknowledgement that eg. transmascs can enjoy vaginal penetration, I think there's a tendency to assume that this is just a vestige of previous interest, or a natural extension of having a "woman's body," and not an actual physiological change that a "masculinizing" hormone can instigate. Which is pretty cool, and has some interesting disruptive implications for how we conceptualize gender.
All of this is to say, I understand the context behind why people lament the prevalence of trans guys vaginally bottoming in erotic fanfic - its overrepresentation in filmed commercial porn, the default expectation from real life sexual partners that being transmasc automatically indicates an interest in that kind of sex, etc. - but I really, really, really would like people to be a bit more careful in how they approach this topic and bear in mind that this is not only a real preference that people can have, but one that can feel specifically trans- or masculine-inflected to those people. And that this preference is already a cause of significant dysphoria and shame for many.
















