Fight or flight

I've liked this girl for four years and she's always had a boyfriend. The same one (now living together). She finally told me she likes me and wants to be with me. Rejoice! She wants to end it with her boyfriend but she hasn't. She's having trouble. When we were finally open about our feelings and stuff, she kissed me.

This is what our first kiss was like. Literally 4 years of attraction, flirtation, and desire thrown into one kiss. And it was amazing.

Now whenever we hang out, she kisses me. Not complaining, but I need more. We need to take the next step. Then she tells me that she wants to be with me extremely badly and I'm all she thinks about. 2 things stand in her way:
- Her family won't let her live with them temporarily
- Her boyfriend is trying harder now. She's not optimistic about it at all but she says she owes it to him, herself, and their long relationship to see if it works.

But after that, she still kisses me. Every time we hang out. Last time we hung out, we drank together and everyone we met thought we were dating. And she didn't argue with it; she played along and it was fun. We made fun of each other as if we were dating and it was a blast. But she always feels bad the next day. Not enough to stop, but enough to feel bad for her boyfriend I guess.

She asked me (kind of begged) to wait as long as I can for her. I agreed to but I just don't want to get screwed over. I don't want her to keep kissing me and dating him and never change it. This is hard because it's actual love for me and I'm stuck. What the hell do I honestly do here? I can't speed this up as far as I'm concerned. It's the dream girl, everyone. I was almost engaged and I never felt for her how I feel for this one. It's real.