Boyfriend Liking other girls Bikini photos?

I have a boundary that in a relationship I dont tolerate my boyfriend to like other girls bikini photos. Especially girls that he had a past thing with or relationship with. However, after I told him that boundary about 3 months ago, I found out he's been liking other girls bikini photos still and his excuse was that "he sometimes mindlessly scrolls and Iikes things without realizing" or that "he like the girls bikini post because she was traveling to the same place we were at the same time in Spain" to me those excuses dont add up and aren't good enough. But he got upset at me because he feels im just constantly nit picking him apart and that he's been putting in so much effort to not like that type of stuff but no matter what he does isn't good enough and that my expectations are too high and that if he slips up once ill get mad at him. My argument is that even after having this conversation with him three months ago he's still crossing my boundary. But his argument is that he's been putting in the effort to try and not like that stuff and that sometimes he slips up. I dont know how to feel. Part of me feels like im being a bit ridiculous, but another part of me feels like im being manipulated. To me, guys only like girls bikini photos because they see what they like. His argument is that, thats not true and that just because he likes it doesn't mean he finds her attractive. And every time I bring up something I see, instead of just getting an apology and having a conversation he just gets very angry and defensive.

Boyfriend Liking other girls Bikini photos?
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