This is a tough situation.
Personally, I've never been in that kind of situation.
My first advice is to stop worrying about the sex part. A lot of guys make the wrong assumption that it is having sex that makes you not completely straight. That is totally untrue. With whom you sexually penetrate (or are penetrated) has NOTHING to do with whether you are gay or straight. I know that seems counterintuitive. But honestly, you sexual identity has nothing to do with where dicks get put. It is about who you are as a person and that doesn't change, irregardless of any penetration (or lack of any).
I am NOT going to tell you what your sexuality is. That is totally up for you to figure out and is totally unfair for ANYONE to tell you otherwise.
You have developed an intense emotional attraction to another guy. What you need to figure out is whether you want to see if it can move beyond very close friends. You do not have to have penetrative sex in order to be in a gay relationship. You mentioned that you would kiss him. Does that mean that you want to kiss him, or that you'd let him kiss you? This is key. You need to make sure that both of you are on similar pages.
It seems to me that you are more okay with the idea of a gay (or bi) relationship with him than the idea of gay sex. If that's true, then you need to ask yourself what is it about gay sex that bothers you. The two of you have already jacked off together. That in itself is not necessarily gay, but it could be. It is more about what was going on in your head than anything else.
The two of you are in the opposite position of what most guys in your place would be. Most guys would be more okay with the sex than the emotions. The problem I foresee is that he might seems to want more than you do from a sexual standpoint. If you are willing to pursue this relationship (and remember you CAN be in a gay relationship without penetrative sex, either oral or anal), you need to make sure that the two of you are close enough to the same page. The worst thing that can happen is that he begs you to let him blow you and you let him do it, but don't feel comfortable reciprocating. At first, it will seem okay to him as his sexual desires will be that strong, but after a while it won't be enough. You can't have a relationship with someone you care about by just letting them blow you on occasion (with all due respect to the 20 some odd "cocksuckers and the men who use them" threads, that isn't a mutual relationship). If you due pursue a relationship, and are willing to experiment more, please respect him, by not letting him touch you if you aren't willing to touch him back.
Lastly, I just want to reinforce this, being gay or bi, has nothing to do with anal or even oral sex with a man. Its not the sex that makes you gay, you would already be gay or bi (but again, I'm NOT saying you are, only you can determine that). Its the feelings inside that determine your sexuality.
My advice is not to worry about the labels so much and go with your feelings. It seems as if you are interested in pursuing this relationship a little bit further even if just on an emotional level. If not, why did you start this thread. Make sure you talk with your roommate and let him know all of your feelings and reservations. He has a right to know. Respect him enough to do that. If you are willing to try something more sexual try jacking each other off, kissing, making out, and maybe even frottage. None of these involves any penetration for either of you. You can then figure out if you are interested in going any further. But make sure he understands your feelings and that if you aren't willing to do X he knows that and DO NOT let him to X to you.
