<human>: Could you distill the essence of the text into 1-3 sentences?

First post here, thanks for the read. So the boyfriend and I have been dating for almost two years and I've acknowledged this situation on several occasions. Often when we're out in public or are watching a show together he'll often go, "mmm" when an attractive girl is around or he'll comment lightly on her ass, Tits, etc. 

I don't have the best self esteem or confidence in myslef and this seems to make it worse- he knows this. I've talked to him about it and how it makes me feel, he says he doesn't do it to make me feel bad; he loves me and he's with me. 

I also don't want to be that irrational girl that gets upset over minor things, we are human everyone looks. But when he says stuff like that I retract and get grumpy/sad. I think it's a very unattractive trait of his and I've told him at least four times throughout our relationship how it makes me feel but he doesn't seem to stop. 

I've discussed it with a few female co-workers, a very popular comment was the "the strike rule". I love him dearly and this is just about the only thing that gets under my skin. 

What would you do in this situation? I'd love to hear both Male and Female points of view and what you'd do. 
Thanks for reading!
<bot>: Boyfriend won't stop commenting on other womens' attractiveness in front of me despite me expressing my feelings about it- multiple times.