do I have a right to be upset?

So, my boyfriend recently was at work, and I was with him waiting for him to get off (I'm 17, he's 18, so our time together is limited that's why I sat at his work all day). He works at Jimmy John's and he was talking to his co worker about some "hot chicks" that came into the store one night right before close, and he only served them because they were hot. all of this being said right in front of me. I understand that there are more attractive people out there than me, and I don't expect him not to look, because we all do, but do I have a right to be upset that he talks about it in front of me? It seems to 'slip out' a lot, and it honestly hurts my feelings, and he knows that, but at the same time I don't want him to feel like he has to censor himself in order to avoid upsetting me, because he does censor himself a lot now and It makes me worry that he feels like he can't be open with me.