Start this off by sayin I have a girlfriend of 19 months, we're totally into each other still, love seeing each other any chance we get etc. Now along comes another chick and she's really nice, but no way I'd hit her, maybe if I was single, but no chance in hell I'm losing what I've got atm. She's sending off signals that she's into me, and me being a nice guy, don't shut her down, just play along but without sending anything back, but this is one persistant chick. She doesn't know that I have a girlfriend and I think this is what is motivating her to continue. Now my question is: How can I not hurt her feelings but still stay friends? Is that even possible? Like I don't just want to say in the middle of a convo "Look mate, I've got a girlfriend" and I don't want to lead her on (which I hopefully am not). Any advice?