Ladies!! What should I do about my ex girlfriend?

I've been seeing my ex girlfriend again for 3 weeks and have wined and dined her. She knows I want to get back together. I came to meet up with her at a bar and she was in full force flirtation with some guy grabbing each others arms and really pushing the limit. After I got her attention, I acted really cool and didn't even mention the guy. So, do I bring it up now 4 days later? I don't want to be the chump wining and dining her to get her back for good while she is acting single when I'm not around. Should I tell her it bothered me and I'm going to see other people in addition to working on our relationship because that's what she has been comfortable doing? Please help!