sending nudes

Let me start by saying husband is awesome. I trust him 100% he would never cheat, doesn't look at porn or anything. We discussed before we got married that porn wouldn't be okay in our marriage. I use his phone sometimes or when it goes off ill check it as he does the same with mine. The past month 3 of his idiot friends send him pics of naked girls. I know the one only does it because he knows I don't like it. It makes me so mad, I feel disrespected by these guys who think that's okay. .I can understand if he was single but HES MARRIED. like why are people so inconsiderate of other people and their feelings?! Does this make anyone else mad or am I the only one?