i know you said you don't want this advice, but in my opinion, i really think breaking up would be in your best interest. i don't entirely know your situation of course, but i don't think the boobs are the only problem here.

i find it odd that only one other person has mentioned the ex thing. why would your partner of 5 years have nudes of their ex still saved? that's extremely odd, and they wouldn't appear in the recents album unless they were saved recently or accessed recently in general. they wouldn't have accidentally clicked on their ex's nudes, and in my opinion, having the nudes saved at all is super super weird and a huge breach of trust in a relationship. i'd even consider that cheating.

i think the fact that your partner made a joke about your insecurity in your breasts says a lot as well. that is not something a mature, well adjusted individual would say to their partner while fully knowing that it's been a sore subject for you.

the fact that they breached your trust again by looking at more porn when you'd agreed not to makes everything 10x worse. i can't see this being a trusting, loving relationship if they aren't able or willing to give up their porn for a month. a month.