I have been seeing this girl for about a month now. She has spent the nights with me often and started having sex two weeks ago. I have since met her sister. She comments how much she looks forward to spending time with me and enjoying eachothers company. The other night she was drinking and told me how she would have liked me to be at the party for someone to kiss on new years, I was working. She spends that same night after I got off work with me. The next morning she tells me she made out with her female friend. I talk to her about it and she says it is something that happens when she drinks but has and will never do anything more with another girl. My issue is that I have been cheated on in the past in the same manner so I see no difference between a girl or guy, still cheating. But me and her aren't exclusive so I know it isn't cheating. But she has told me she is interested in a serious relationship and shown interest to invest her time with me. But tells me had I been at the party she would have still made out with her. Is this something I should continue with or am I looking at future problems dealing with someone that has this type of mentality?

Just do not make decision so fast... how about think of this question two months later?

You have been seeing her for only a month but sleeping with her for about two weeks of that time, she makes out with people when she drinks (since she said it was something that happens when she drinks), and she says she would have made out with the girl even if you were there.

Does that sound like someone interested in or ready for a serious relationship to you?

If you like her, and enjoy spending time with her, continue to date, but personally I'd hold off on thinking about anything serious at this stage. You moved really fast, but you are still getting to know each other. As Jessicacn said, give it more time... see what you think in a few months.

If you are interested in a more serious relationship with someone, you might find you will need to keep your options open and keep looking.