HELP !!! I Need advice!!!

Ok so I’ve been dating this guy for about 6 or so months, our relationship is great however I’m having a hard time trusting him about one of his female friends. Usually his female friends are actually very boy ish & really cool people, but this one just won’t back off, she’s constantly shouting him out on social media’s, send him photos that aren’t really nudes, she was in her underwear & I wasn’t happy about that. It’s kinda confusing tho Bc she also posted it on her social media.. idk should I be worried?? They haven’t really done anything together, but a few months ago they got drunk at some kids house together & my boyfriend wasn’t answering his phone so I directed messaged her the next morning & she lied to me about what happed. She claimed that they feel asleep watching a movie together. I was later told by him what actually happened, & I don’t trust her. But should I take action & talk to him about it or leave it alone.