Insecurities please help me

haleigh
Hello. I struggle with sever insecurity issues after having many different things happen in a precious relationship then in this relationship my bf was talking to other girls online, complimenting them and exchanging pictures. I have control over all his things so I know he is no longer doing that but I catch him looking at females butts and boobs frequently and know him and his friends constantly talk about other girls and the way they look. I need help and need to know if I should take this as serious as I do or if I should just let it go because it's just looking and fantasizing and he's not acting on it. He's not talking to these girls or having fake profiles anymore. I don't know if I should accept my bf looking and talking about other women, I need advice please!!!