Stop thinking about competition with your other gay friends.There is no greater reward than gaining his trust. This way you can learn more about him, even his juvenile days and well, sexual fantasies which you can make into a reality when the right time hits.
Remember that as a straight guy, he is still confined in a society that is not open to such acts. Once he found out that you spilled the beans, I can guarantee you that he will never want to talk with you ever again. I know you don't want that. So just savor the moment that you had last night and keep his secret until he is ready to show the world what he is really made of.