Me and DP been together 13 years 1 DC, had a few issues last 16 months not getting on, arguing, no love. Then few months back I find that he had been having an affair for 4 months. That killed me, threw him out was hard to even look at him, what hurt most is that he had an affair with a much younger guy. I never even know this about him thought after so much time together that we knew each other inside out. Found out that he had met up with him even after all this had happened. A lot of damage was done but chose to take him back, we went for a few sessions of counselling see if that could help. But I can't trust him, I constantly check his phone, his emails, or where he is and go home during work just incase he's up to something. I just don't know what to do, we aren't married says he'll never marry me and scared he'll go back to be with him if we finish things for good, feels last 13 years has been a lie