Help! Boyfriend has naked girls on snapChat

Sabrina
Last night I went to post something funny from my boyfriends snapchat, and when I went to where his stories are, I saw one story from some gross chick posting videos of her touching herself, pictures of her in her underwear, and up the skirt piks! I immediately removed her from his friends (even though I know he doesn't know her personally). Then I saw another story from a user called "daily cream pie". I knew he watched porn (duh, he's a guy) but on snapchat!? And I don't really know how to react! Especially since one of the users was a specific girl. Even though he doesn't know her, he likes her enough to watch vids of just her, right? What should I do?