Should I be mad.

Should I be mad if my boyfriends friend (guy) sent him a picture of a girls vagina/nude? It might be his friends girlfriend but doesn't look like her. Do I have a right to be mad. 
He's with him right now so he probably told him to send it to him. So I'm angry at that. 
I saw because he left his Facebook logged in with the convo up 🙃