!!!!!

So me and my daughters dad have a great co-parnting relationship, he was/is the loml, but our romantic relationship ended horrible anywho him and I haven't slept together in over a year (been broken up 2 1/2 years) well the other day we got into a little argument and I told him that I didn't have romantic feelings for him anymore ( I do , I just don't want him to know) than the next day I seen him and we were at my house, I was rocking my daughter to sleep and he decided to lie on my lap, and be flirty that whole day, so the next night my daughter wanted him to stay the night so he did and when she went to bed things got hot, we started flirting more and one thing led to the next, well I just don't understand why he wanted to have sex when we haven't been intimate in so long, we don't even hug. Is it a confidence thing for him? Was he trying to prove me wrong ? Was he just trying to see if I'd give in. Was he just trying to make sure he still has control of my feelings ? Now I'm just confused and wondering why he made a move ( don't get me wrong it was great and I wanted it to happen) I haven't asked him why or said anything about it to him. Maybe it was just a little fun and it wasn't nothing and I'm overthinking it.