I'm in a roughly similar situation. I really like this girl and have done for quite some time (about a year). Now i've seen other people since liking her but I still really like her. Im really frank with her and she is with me, were pretty close friends and she's never closed the door to us having a relationship infact, she's hinted towards it sometimes. Shes not single at the moment, and has been with the same guy since I met her. Their relationship isnt perfect, they argue alot. Shes really considered ditiching him a few times as well but hasnt. It's just that theres such a connection between us two (much like you and your girl Dan). Once at a party we kissed and it was almost a 'one thing lead to another' story but we stopped short of sex. But there was so much chemistry that night. Its driven me mental ever since haha And yes poopipe, its called negative reinforcement funnily enough. Same thing was used to 'cure' homosexuals not too long ago.