What should I do about my flatmate?

Right, well this is pretty complicated. Bit of a long one - sorry in advance! So I'm just starting my second term at uni, and last term I broke up with my boyfriend because it just wasn't working out. I have a flatmate with a girlfriend, and he's a really good mate - we both have insomnia so we stay up late together and have a laugh. But one night we got too drunk, and ended up fooling around. That would have been fine, and we could probably have forgotten about it, had it not happened again before christmas, when we went the whole way. Not only that, but it was more than just sex, he kept saying all of these romantic things which made me think it might have meant something more. I obviously felt terrible, as he told me he was having problems with his girlfriend, as she's seriously depressed and he doesn't feel like he can handle breaking up with her because he's worried she'd do something drastic. So we talked about it and I said that he really had to work on solving his problems, so it wouldn't happen again. I of course assumed that he was only really using me as a release. I know I shouldn't even have considered him, but then I found that I couldn't stop thinking about what had happened. I just attempted to convince myself that he didn't like me over the christmas break so I could go back and start a new, clean slate, and so I could work on getting over him. Sadly, however, last night we got back after a drunken night out with our flatmates, we were having a friendly heart-to-heart, and apparently things with his girlfriend haven't been getting any better, and what's worst is he then told me he really likes me - and I admitted that I liked him too - and then he suddenly began to kiss me and I stupidly let things go too far again. I have no idea what to do now, we're just acting like friends during the day and around the others, we haven't talked about it, but given that it's already happened 3 times before, it'll probably happen again. We live together, I see him every day, and we go out as a flat all the time, so it's impossible to avoid him. I can't pressure him to break up with her, I don't deserve to and it's not my place, but now I feel like I really like him and it's all I can think about. So yeah, that's my life. Any outside opinions would be great...

I think that you should not let things go too far again. It really isn't healthy for you and him because he needs to work out his issues with his girlfriend, and if he can go to you whenever he has those issues, then it does not solve any problem in his relationship. It is unfair to you, it's making things more complicated for him, and it is not fair to his girlfriend. Even if she did decide to do something drastic, that is HER choice. It would be better to break up with her than to live a lie. Since the girlfriend does have depression, I hope she is receiving professional counseling or therapy for it. If he ever wanted to break up with her, he may want to encourage her to get counseling before he does it. I realize that you care about him very much, and that is why you should not have any more intimate moments with him until he decides that he wants to break up with his girlfriend. You shouldn't force him into making a decision, but at the same time, you have strong feelings for him. If you are fine with being the woman on the side, then that would be one thing, but from reading this, I know you are not. Your actions right now are telling him that it is ok. Since you don't know how long this will continue, you need to make a decision now and stick to it: 1) Continue the way you are now, accepting that it may not go any further than that or 2) Tell him you have feelings for him, and for his sake and for yours, you two just need to be friends at all times. TILES