I need a girl's advice, please !!! OMG!!! WTF!!!!!!!!?

So I started this job about a year ago, and there was this receptionist that was smoking hot!!!! However, she was quite the *****, never acting the least bit interested in talking to me. Well, here we are today and she's put on a few pounds. She's not real fat, but she has a well defined muffin top. Now she's all touchy feely, always talking to me like I'm in her league now. Should I just tell her to F*** off or should I take her out? I know she treated me like s**t in the past, but I could tough it out and take her jogging. Then she would lose weight and I would have a smokin hot girlfriend!!!! Should I keep my dignity or go for it? Thanks.