My boyfriend liking pictures of half naked girls?

So me and my boyfriend have been together for four years... And he keep liking girls pictures that have their boobs hanging out that I know who are pretty easy.. And I've told him several times that it bothers me and he continues to do it... he's cheated on me once like about a year ago so it makes me worry about it more... I know I shouldn't worry but I'm a extreme worrying type of person. I just want know how I can stop stressing over this so much...
My boyfriend liking pictures of half naked girls?
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