He probably still have not gotten a good dicking yet, once he accepts he likes dick and has some good sex with a man (or a trans woman) he will be doing more and more anal play trying to emulate that pleasure
There's a few hung trans women who like femboys, for example Gia Itzel, i'm sure if he asked her or any other for a collab they would comply, he's pretty cute. He just needs to take that step