<human>: Crushing for a while, gave in last night and feel terrible about it. 
 
She's been with another guy going on 4 years, no idea if she's cheated in the past.(based off her being with me I'd say it's not that big of a stretch that it's happened before)  
  
Even if she breaks up with him- can any good come from us being together?  
  
We haven't talked much about it but I'm pretty sure she's thinking she can stay with him and be with me- in the past I've told her that can't happen and put her off but succumbed last night.

Can you provide a brief overview of the text?
<bot>: I don't want to drop her completely after being intimate, but can't rationalize being with her seeing as she's cheating on her bf.