Is their an �inconspicuous� way to ask and find out if another male is gay or bi?

i have recently become friends with another guy who i believe, like me is bi or gay. i really want to find out because i think i am starting to develop feelings for him. i have always had an interest in him and have known him a while but know i want to know him even better than before!! is there some way i can find out if he is gay or bi? anything i can say without sounding gay or bi myself? any tricks to use? some kind of test? i am willing to try absolutely anything except straightforward asking him out!! please help, i am desperate!!