Although I have my doubts based on the original post, I'm going to assume the question is a genuine one and not an excuse to show photos of, or discuss the physical attributes of, a stranger.
First, you characterize "broaching the subject" of "convincing" him to experiment sexually with you as a delicate one. If you are gay and attracted to him -- which is evident -- and he is gay and attracted to you -- which is yet unknown -- then you have nothing to lose by simply saying words to the effect, "I am attracted to you and want a sexual relationship. How do you feel about that?" If he is attracted to you and homosexual, then the answer will be "yes" and you can get on with it. If he is not attracted to you and homosexual, then the answer will be "no" and you can get on with it. If he is not homosexual, then the answer will be "no" and you can get on with it.
Second, there is something desperate and disrespectful about "convincing him" to have sex with you. A better approach, which respects his sexual orientation, whatever it is, would be to ask him his sexual preference, as I suggest above. Surely, you must know that attempting to convince someone to have sex with you is bound to be unsatisfying at best and an utter failure at worst.
In the meantime, spare us the photos. You want to have sex with him, not us.