My new boyfriend lied to me, and I don’t know what to do.

I been going through a really bad heart break for a year, and recently just got over it... and there was this one guy who was always there for me.. for nearly 3 months he waited to get into a relationship w me while we were just more of best friends w Benefits. I finally gave in about 8 days ago and we’ve been going out. The other day we were gaming together and his WiFi all of a sudden went out, and he told me he just was gonna go skate... he was gone for a few hours and then when he got back, he told me he needed to help his dad w something, which took an additional 50 minutes. The next day (today), some girl tagged him in a post with them taking photos in his bedroom from the other day. I don’t know if I’m overreacting or being insecure, which I’m usually not the jealous type, it’s just the fact that he lied to me... He ended up telling me the truth and saying he was just scared that I would’ve got mad, and told me they did nothing and it’s just one of his really close friends. And she just happened to be at the skate park and went to his house so she could wait for her Uber. What do I do? Do I cut him off? Choose to trust him? Please help me