Hey all!

I have a question for you with a girl. It's not a regular one - it's not about lack of confidence or something like that. I met a girl who i've been living for 10 years next to. but only 2 days ago we had a first conversation. I asked her out she did not reject so we had a really good time. Then we came to my place but there was nothing happening between us as i knew she has a boyfriend. Actually, her relationship recently hit 5 year mark. But this fact, you as may realise did not exclude ascending tension between us. I led our conversation to talking about early relationship chemistry and excitement and then i asked her whether she feels something like that to me. She told that surpisingly but yes: surprisingly because she hadn't felt something like this for years. Then at 4AM i released her to go home. I met her bf who somehow considered me as a cool guy especially after reading our chatlog via her account as she carelessly left it logged in. I feel myself confident enough to start relationship with her but it's not about it. There were in my life some circumstanses that i had to break someone's relationship. Surely i always felt uncomfortable but i could do nothing about it - but it never came as far to 5 year rel.

What would you do if you were me?