Dealing with jealousy....

So my boyfriend and I have been together for a year now and I love him more than anything. Before me he had a girlfriend who he’d been with for 2.5 years. Through that relationship he was constantly getting hundreds of nudes from dozens of girls and lying to his gf about it. I actually met him bc we went to the same school and he wanted to hit me up to hook up or get nudes. But I knew he had a girlfriend so I made it clear I wasn’t that type of girl. We actually ended up being friends and he would jokingly-but-not ask for nudes from me or from some of my close friends. Anyways so there was one girl he had more photos from than anyone else, let’s call her Blondie. After my bf broke up with his ex, him and Blondie were still hooking up regularly and it got to a point where he had over 1,000 pictures of her saved on his phone. So when he and I started seriously talking about getting into a relationship i had a few tough decisions to make. I didn’t know whether to tell him to not receive pictures from other girls at all or to ask him just to be honest with me. I didn’t even know if it was a good idea to date him because of his track record. Anyways, so recently I’ve noticed her name has popped up on his phone as text messages more and more recently and I don’t know how to bring it up.

Recently he’s also been trying to reconnect with old friends, and all of them just happen to be girls. Mainly one girl he’s known since he was a freshman in high school (he’s a senior in college now). I don’t know if there’s anything going on between the two of them. Every once in a while he randomly texts me to tell me something that’s happening while he’s getting dinner with this girl. I don’t know how to tell him that it makes me uncomfortable when he goes out to dinner with girls without telling me or inviting me without sounding completely overbearing and jealous and like i have trust issues. I want to trust him. I just don’t know how, considering everything. What should I do?