‘26M’ ‘24F’ guy friend keeps flirting with my gf what is the best solution for this?

We’ve been in a relationship for four months now, and there’s this guy who constantly replies to my girlfriend’s Instagram stories. His messages are usually things like “You look so cute” or “Your eyes are so fine.” Most of the time, she either says thank you or just leaves him on seen, but he never stops.

She actually showed me their messages before Valentine’s Day while we were just watching videos on her phone. I didn’t think much of it because she always shuts down the conversation or ignores him. But on Valentine’s Day she posted a picture of herself with the flowers I got for her, he wished her happy Valentine, and she responded with “You too and asked him any valentines plans bro?

That’s when he said, “I want you to be my Valentine, but you ditched me lol.” My girlfriend replied with, “You’ll find someone way better than me,” but he kept pushing, saying, “I just want you.” She left him on seen after that.

Later that night, she posted a picture of us having dinner, and he still had the nerve to comment, calling her cute again. She ignored him, but the funny thing is—this same guy congratulated her when we made our relationship official four months ago. Plus, he doesn’t even live in the same country.

Now, we just joke about it, and I’ve asked her what’s up with him—why he keeps responding like this. She told me, “I don’t really reply to him, I just say thank you, give him one line replies or ignore him,” and even offered to remove him if I wanted. I did tell her I don’t like this to which she thought I am blaming her so I reassured her that I am not upset or mad at you but at him for his creepy messages.

The thing is, I do want her to remove him, but I don’t want it to seem like I’m telling her to or she’s removing him for me. He’s clearly crossing a boundary and I just feel like she should either remove him on her own or at least tell him to stop.

TL;DR guy friend keeps DM’ing my gf. My gf leaves him on seen or says thank you. But on valentines day said things I didn’t like. Do I need to talk about this to her or just let her handle the situation?