Help please.

What do I do guys. I’ve been with my boyfriend for 7 months he’s never cheated or talked to any other woman but a few weeks ago I caught him looking up a girl on Facebook.. whom I’ve seen him search before. I finally confronted him about it and he said he didn’t remember looking her up and said they never messed around in a sexual or relationship type of way.. I let it go. I went through his phone and found out they indeed were together for two months and also were having sex.. my feelings are extremely hurt because why would he lie about that.. why would he be searching up a woman he had sex with and pictures with etc.. then also I saw that him and a woman my child’s father cheated on me with before he accepted her friend request after I’ve voiced to him the situation.. should I cut this off.