I'm yet to find a shemale lover, so I can only speak in terms of fantasy. I'd want to try both; but what I think about mostly is taking the cock and sucking the cock of a gorgeous TS girl.
There's a great video on the internet of Yasmin Lee with this guy bound up at the start, and Yasmin Lee is playing a kind of dominatrix role. My ideal fantasy would be: being that guy!
So I chose "bottom".
