This will sound like a ridiculous question!

In my life I have had probably two significant romantic relationships. One with a boy, and one with a girl. I'm currently single and have been defining myself as gay... I'm romantically attracted to men, but I think not sexually.

However there is a man I like. He's a good friend, and he's very attractive, nice, creative and all that. I would like to get with him, but there's a mental block as far as sex is concerned. He is very comfortable with his sexuality and I am not with my own. He knows that, and I think he quite likes the challenge... he likes to think he will be the one who will open this new world of pleasure to the reserved-librarian character. I worry about boring him, but that is not what I am here for.

My question is, if someone else is going down on your or whatever, what the hell do you do? I mean, with my body or my mouth or whatever... I don't know how to respond apart from verbally, and I feel like that doesn't cut it? I don't know. I guess I mean, what is to be expected from the 'receiver'?

Sorry for the awkward-textbook sounding wording