Double Whammy of Confusing Crush-ness

I am so "out" it's like I was never in the closet. I came out a little over a year ago and since then, I've been the token lesbian in my little group. But see, the thing is, I haven't really explained to too many people that although my general label is gay, it's just a best-fit term. I'm a Kinsey 5 and do (very very occasionally) feel sexual and emotional attraction to guys (though usually not both at once, so it's never really been an issue).

Until now? (dun dun DUN...)

I've had a vague attraction to one of my guy friends for quite some time, but since we never really spent a lot of time together and were always in a big group when we did hang out, it never really occurred to me that that's what it was. There have been signs, of course, that I largely ignored. Like, I'm always totally psyched when he shows up. I love when he hugs me, it's both comforting and a little exciting. I love to make him laugh and always feel accomplished when he finds something I say funny. And once, I had a sex dream about him and then blushed furiously when he walked up the next day. I told him and he laughed and joked that it was a triumph for him because it was the closest he was going to get to getting in a hot lesbian's pants.

So this has been possibly building for a while, but fast-forward to these last couple weeks, and the shit has hit the fan. My guy friend just went through a rather messy breakup and in order to keep himself busy, he's out and about with our friends all the time now. Thing is, this leads to him and I being the only ones around at the end of the day. We play cards and talk about life and talk about his ex-girlfriend and his situation and stuff that's stressing me out in my life. We check up on each other because all the life stuff and time we've been spending just chillin' has brought us together.

The last couple of days have been strange though, I think, for both of us. He and I will be doing some after-hours chatting in the place we usually hang out and he puts his arm around me and I lay my head on his chest. There have been a couple times where I thought we might kiss but we both sort of carefully, actively didn't do it. We even talked a little bit about the tension between us in a way that didn't really say anything. He just said he didn't want me to feel like he was using me for comfort while he's hurting and I told him I didn't want him to think I was preying on him now that he's single and vulnerable. But we didn't really talk about what any of this means or what it is at all. And nothing really substantial has happen, it was just a subtle change that makes every touch, every hug a little more intimate than friendly.

And all this has awoken something in me that's terrifying. On one hand, my concept of my own sexuality does, in fact, allow for this kind of attraction--but everyone else's concept of it probably doesn't. Which I know shouldn't matter to me, but it does. And on the other hand, I don't know what it is that either of us want out of this. I tried to imagine myself sleeping with him and I could, easily, but actually dating, I don't know. Not that I'm not emotionally attracted to him, just that now isn't really that great of a time for it and it's not like I'm in love or anything. And honestly, I don't mind being an fwb. I don't mind him taking comfort in me when he's hurting because that's sort of what I'd be doing too. It would be like an "I need someone, you need someone, we're good friends, let's do this" kind of thing.

I know I need to talk to him, but I feel like I can't sort it out inside my head so how am I supposed to explain it to him? And when is a good time to talk about this? And should I even say anything about what's been changing between us since nothing outwardly has actually changed (since we haven't kissed or really expressed anything openly)? Should I back off? Should I just see what happens?

I'm not sure if any of that is actually even clear enough to be understood, but I'll fire it out into the ether anyway.

We'll both be at the same party tonight--there's no alcohol involved, so that's good--but I'm nervous and changing my clothes a lot, which is a bad sign.