You are in a bad position is what you are. Even if she does think of you as a relationship possible, she is tainting it by making you "the other guy" in this situation. More than likely she is using you to make herself feel like she is either in the right, or supported in her opinions and decisions (depending on the situation). With you she probably feels like she has comfort support, somebody who makes her feel perfect and that they will do anything for her. That may mean you are doomed to be the guy she runs to every time, but nothing ever happens with.

It is really difficult for somebody not knowing all the details of the situation to tell you what the answer is, the only thing I can say for sure is that if she has a bf and they are not in an open relationship he would not be ok with her running to and cuddling on the couch with another guy. It is probably something you should avoid. Let her relationship play out the way its going to, be ther for her if you need to be, just draw a line at friendship, maybe tell her if she wants more from you that you are open to it, but not while she is in a committed relationship with somebody else. If you are going to date her you want it to be all of her not just whatever part of her is not consumed with her other boyfriend.

Hope that helps?

I'd say your the friend, but in that respect she obviously trusts you alot to come to you with these issues..