Yoo, I'm Confused

A female that I had been in a serious relationship for 4 1/2 years broke up with me about 6 months ago. But here's the story, When she left she got with somebody 2 weeks after, but during that time she kept seeing me.

1.) She went on vacay and I was the first person she saw. (Jan)
2.) She kept stopping by my house even when I wasn't home. (Jan)
3.) We had sex when she started seeing this guy. (Feb)
4.) She called me a lot and still does.
5.) She had sex with me in Apr. because he gave her a week to do what she wanted to do.
6.) and every time I see her she looks kinda of bad.
7. ) She says she's happy but she said she misses me on multiple occasions.
8. ) she told me he did some dis tasteful stuff that 99% of couples would break up for, but she stayed.

Somebody help me, Please!!!!!!!