<human>: Could you distill the essence of the text into 1-3 sentences?

This guy and I have started dating again this past 2 months. (our duration of dating on and off was 4 years.) Last year he was dating this girl in his home town. I always blew up on him if I found out he was seeing her or anything along that sort but we weren't dating again yet. He moved away from his parents house now 7 hours away. This past weekend he was there to figure out family problems. I had anxiety all weekend where he would see that girl so I kept asking him each night if he's seen or talk to her and he would always say no. 

Last night he went out with his cousin and couple friends and I asked him again before I went to bed if he saw her because of that fear. Didn't get a text from him all day today and I texted him at 1pm, he replied and was sleeping on the train back to his home. He said he was out late and drank more than the rest of the weekend. And his brother joined in later that night. 

And then I looked up her social media ( which I did all weekend ) and today I see a video of hi in a bar setting for her bday shindig. This made me so livid, I blew up on him. He was going to keep this from me for who knows how long. I cussed, I ranted, I hated him.Called him a liar, everything came out over texts.  

And He admitted he couldn't tell me he ran into her and that I was overreacting for something so small since her friends are his friends too. & that they ran into each other. He admitted to not telling me about it since I would blow up on him. That's not fair for me at all. 

How can I date someone I don't trust? Can you get over this? 4 years of up & down history and then this happens.
<bot>: Dating for 2 months again after on and off for 4 years, he can't tell me the whole truth because he thinks I blow off over everything and now I can't trust him.