my suggestions...

1. ask him -- what's your 性傾向: 1) m to m; 2) m to f; 3) 2ms to f; 4) 2fs to m; 5) exchange own f with others' fs...

2. ask him -- what's your 性別: 1)M; 2)F; 3)was m, now f; 4)was f, now m; 5)outside f, inside m; 6)outside m, inside f; 7)not say; 8)wanted to be m, but is f; 9)wanted to be f, but is m...; 10) top is f, bottom is m; 11) top is m, bottom is f...

3. ask yourself the same 2 Qs above and provide your feedback to us...

enjoy!