<human>: My boyfriend and I have been together for 2 years. We met online and we've been long distance for roughly half of our relationship. We're currently long distance and will be moving in together again at the end of the month. We have always been incredibly happy together and I have literally never suspected infidelity from him once. But recently that's changed... 

We used to be attached at the hip and would talk all the time which is really important in a long distance relationship. But about 2-3 months ago he got a job and now has a new friend group. Don't get me wrong, I'm glad he has good friends who he can really get along with. But recently it seems to me he would rather spend time with them than with me.

He stays out late until 2-3AM or just doesn't come home at all. I didn't have a problem with it at all at first; but it's starting to stress me out. I don't know if he's actually acting different or it's all just in my head. Especially because I recently discovered that his ex works there too and I'm fairly sure she's part of his friend group? He's told me about all the people who work there but for some reason he has neglected to mention her name. He's also always quick to change the subject when I ask him how his night was/what they did. To me, this is sketchy behaviour. Can someone else give me some insight on how to handle this situation? Thank you xo

Give me the gist of the text in a nutshell
<bot>: boyfriend has been spending an increasing amount of time / late nights with new friends who also include his ex gf (which he neglected to mention)