My boyfriend and I have lived together for 3 years. We plan for the future and generally have a wonderful time together. The other night, I wanted to play him a song - he gave me his phone to play it from and as I went in - a dating app popped up. He told me he doesn’t use it and then gave me his phone to check. He told me I could look through anything. I then went to the App Store, re-downloaded it and logged on. Sure enough, he was lying. He had been chatting with different girls for about a year. None of the conversations turned into anything and we’re mostly ‘hi, how are yous?’ I left immediately and spent the night away from him. I told him I needed space and he went and stayed somewhere else for a few nights. He came back to our apartment yesterday and we talked about a lot of things. Why he felt the need to do this, how long it was going on etc. He has made an appointment with a counsellor and wants to work on things. At the moment, he is sleeping on the couch and we are taking some space. I don’t know what to do. Do I try and work on this with him? Or just let it go? I’m not sure I’m ready to flush three years away but I’m pissed he did this and lied? Do all guys do this ??