ADVICE OPINIONS?!:( I give up

Q:
Annomyous please

My fiancé & I have been together five years … I have constantly expressed my feelings toward him watching porn … I have no issue with it if he’d just watch it with me & not hide it and lie to me about it … he says he just watches it for entertainment I’ve caught him watching it before but he truly wasn’t doing anything to himself but after he watches it sometimes I only know bc our google acts are linked he wants to have sex he usually only watches it when I’m gone to the store for 3-5mins we live right by it but there’s been occasions he’s watched it right next to me I’ve told him how insecure I am and it just makes me feel like he has to watch other women to feel excited or to have sex with me and I told him I don’t mind I just hate him watching it by himself he quit for a long time then started again any ideas on what is going on and why

At one point we had a long talk I thought it was a heart to heart but idk bc he’s done it since then this was when he said it’s just entertaining… but I was bawling exposing how it made me feel & he said he doesn’t want to make me feel that way and promised to only watch it with me but that’s Been broken & I’ve tried any way possible to open up and experiment more doesn’t change anything I was literally in bed next to him naked one time he thought I was sleeping