Ok. I don't know how you let it go this long without talking to her. Dude, she is definitely seeing some other guys on the side. Let her know you know. then tell her she needs to think what she wants out of the relationship, b/c the two of you obviously don't want the same things. Tell her to think about it and call you in a few days. If she calls, great, talk it thru. If not, let her go. I know it sucks, but you'd end up be miserable for awhile until the two of you break up anyway.