<human>: My ex of five years asked me how I would feel if he went on a date with a girl he was interested in seeing. I am confused as to why it would matter as we are nothing more than friends now who sleep with each other from time to time. Some background to this is that it did not end well as we were both not mature during the more serious parts of our relationship but now we just sleep with each other if one of us is in the mood. In the past I would care if he was dating other people but not anymore. I have not brought it up or asked him anything about the matter for a few months. He never really cared about me before and he would tell me things that he knew would hurt me (sleeping with another girl when we got back together) so I didn't really expect him to ask me how I would feel right now. 

I have not told him this but I think he got the clue that I also have started seeing someone new. I have not really reached out to my ex. We used to talk daily but now since I'm seeing someone new I haven't reached out to him as much anymore.

I am just really confused as to why he would suddenly ask me how I would feel if he started dating someone new. We are not dating and we have not talked about getting back together.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Ex asked me how I would feel if he started seeing a new girl and I'm confused as to why it would matter to him since he didn't really consider my feelings in the past.