One of my first gay (I'm Bi) experiences was like that. When I was seventeen, I went over to my friend's place, and she had invited one of her guy friends there too. The night went on with us just hanging around, and she (My friend) eventually had to run out of the house for a bit. So, she drove out and was out of the house. The guy, her friend, and I sat and hung around for a bit, since neither really wanted to get up and leave. He seemed pretty straight, but he seemed to have some gay or metro tendencies. Eventually, we started drinking bear, which then became wine, which then turned into vodka from my friend's parents liquor closet. We sat, not watching porn, but we eventually got completely wasted.
So, we started asking each other inabriated questions like, "How many girls have you hooked up with," and, "Are you a virgin." At that point, I wasn't, but he was. I had slept with a girl the summer before the story. After a few more drinks, I was shocked to find his face right next to mine when we were watching TV. He got really close, and I could eventually feel his the rough hairs on his cheek. He didn't exactly kiss me, at first. It was more of a little lick, near the mouth. But, I made the first, real move and put my mouth to his. We made out for minutes, letting the TV run, and I eventually reached into his cargo shorts (I'm trying to remember this as best as I can, but it helps when it's a milestone). We unzipped eachother, and I was shocked to find that this "masculine" guy wore bikini briefs. I, coincidently, had just switched over to them, from boxers. So, we were both drunk, hard and ready to try something new. We rubbed eachother, still making out, and I would run another hand under his shirt and feel his soft skin. After all that, he eventually let me give him head. If memory serves, he actually screamed so loudly that I was sure everyone else in the Washington suburb was going to hear him. Luckily they didnt, and I was able to get a few hip-bucks out of him before he finished. We kissed a bit after that, I think. But, we just cleaned ourselves up and I stumbled drunkinly home. He stayed over at her house that night, and we still talk sometimes, trying to plan meetings and stuff. But, at this point, I have a feeling that he never actually told anyone the story. According to my girlfriend, he was still "straight" as ever.
I guess the point of my story is that things will probably lead to other moments, if you just let them. Be subtle, but make sure to be aware of what you are doing. If you really want him, go for it, but still mantain a cool, even head. Don't put your hand on his crotch right away, obviously. Just, move closer to him "on the couch," and maybe pass a few drinks around. Not to condone unsafe drinking, but a few shots do help. And if he seems interested, slowely eek in and feel around. Maybe you'll find something
