She loves both of us

Hello
My name is Mike, I am 21 years old.

I started dating this girl for 4 months now and before me she was in a 2 year relationship. We started dating a week or 2 after she broke up with her previous boyfriend. For the first 3 weeks we were dating she was always questioning our relationship because she wanted to get back together with her ex. After the first month she moves in with me and we are both happy. About 3 weeks ago her ex decides he wants to get back together. She decides to go out with him almost every night for a week. We stop having sex when she starts seeing him again. She told me she is had sex with him after a 3rd or 4th time out with him. Then after an argument with our roommate she decides to move back in with her ex.
While living with her ex she is always texting me saying how she misses me and loves me but she wants to give him another chance. After a week or so she decides that she would rather be with me so she moves back in.
After a day or 2 her and the ex start texting each other again. Now she is going out with him every night again they are also having sex again and she plans on moving back in with him in a few days. She told me to give her a month so she could figure out what she really wants.

I believe she is worth the wait but I don't know what i should do.