Yes, of course. I've had many gay friends and there was never anything attempt to start a sexual situation between us. I've also had many female friends with whom there was no sexual wants on either part. I think the idea that a man and a woman can't be just friends is silly, and so I think its just as silly to think a gay man and a straight man can't be just friends.
Though, some of my gay friends would act like they were flirting, but it wasn't a real attempt at anything other than to make me feel uncomfortable. Just like I might tease them about something to make them uncomfortable. Just like most of my straight male friends and I will say horrible things to each other, not because we mean it but because its fun to get the reaction.