Boyfriends!?

Am I overreacting... I noticed my boyfriend turn his phone to where I couldn't see what he was doing.. It wasn't like I was spying I'm laying on the couch looking at him talking and he moved it.. Here is the little story behind things. 
So iv been cheated on in my last relationship and I noticed my bf had a pic of a screen shot of a text message from an old friend lover.. They didn't have sex she's a lesbian who likes to tease guys.. And I guess they had something during high school would make out and sleep over but didn't have sex. I know that Cuz I was his first at age 23. So I seen the pic but went to look at the text and nothing.. So he deleted the message. 
 So I asked him about it he said they only talked about his mom who passed away 2 years ago and he was upset about what she said so he doesn't want to talk to her again. And she deleted her IG a week later and two weeks after that she added him to her new IG. He told me he wasn't going to follow her back but yesterday I noticed he is.