I can honestly say I have never ever thought that any guy who was nice to me was loking for a sexual relationship!
I don;pt really understand why you would think this way.
Making a comparison between men who are nice to mena dn men who are nice to women is utterly meaningless - the chances of a man looking for a relationship with a woman is obviously far higher than in the case of a man looking for a relationship with a man - that's simply the law of averages.
It's like this - if your friend is gay, it will be pretty obvious to him by now that you are not - most gay people are highly intuitive and sensitive (they have ot be living in a hostile heterosexual world) and at least some of the testosterone you scatter around this thread will have reached him by now.
So - either he is gay, and simply likes you as a friend - remember not every gay man finds you irresitable simply because you are a nice looking man - or he is straight, and you are misreading the signals.
Why not see how things go. If he minterperetes your potential as a partner, you can politely and calmy advise him or your orinetation, and continue your friendship.
Don't let suspicion get in the way of a friendship - and don't let unpleasant remarks you leave on here, where you diss an undeserving AB member, and her entire gender, prevent you from receiving some advice from people who are simply trying to help you.
Good luck.