Wow, looks like this is becoming a common scenario. I also took my fiance (God, I *HATE* that word, it's so stupid...not my wife yet, no longer my girlfriend...)...anyways, I took her out of a 7 year relationship because we just fell in love, but I think she was looking for it. She wasn't being treated all that well by her guy, ie. not enough attention, etc. as someone in here had already alluded to. But, I said "fuck it", went for it, knowing she had a bf of 7 years, and it actually worked out. Been together coming up on 7 years now, getting married next September. One of the gutsiest things I've ever done (women wise), but it paid off. He was a nuisance for a few months after she finally left him, calling my house and what not, but I just told him how it was: that she didn't love him anymore, and that they were just wrong for each other, and that he had a whole life ahead of him, one that would be better spent not calling and harrassing me, but out looking for the RIGHT person. Shortly after, he went away and haven't heard from him since.
So to Nedcat, I would say go for it, because you never know...you just may strike gold and find your soulmate. And sometimes you have to fight (not literally, like fisticuffs style) for what you may love and believe in.
But you'll never know unless you try.
Play music, expand the mind, inspire...
"We must embrace pain and burn it as fuel for our journey" - Japanese poet Kenji Miyazawa