I (24m) don?t feel comfortable with my girlfriend (24f) being friends with a guy who sent her nudes and asked her out. Am I being too strict?

I (24M) don?t feel comfortable with my girlfriend (24F) being friends with a guy who sent her a **** pic in past. Am I being too strict?
My girlfriend and I have been dating for 3 months. Because it?s a new relationship, we?re still getting to know each other?s feelings regarding boundaries in our relationships.
Last weekend we came home from a party. She was pretty drunk while I was sober being the dd. We both walked up to the apartment room and realized we left the room key in the car. I sat her down in the hallway and told her I?d be back with the keys.
2 minutes later I?m back and she?s talking in the phone with some guy. Mind you it?s 2am so at this point I?m a little suspicious at who picks up at that hour. While she?s talking I help her inside while she?s still on the phone. She talks for a few more minutes and then says goodbye and hangs up.
I ask her who she was talking to and she says it?s her guy friend from high school who lives in the Netherlands (hence why he picked up at our 2am PST). I kinda jokingly said ?oh it?s your Dutch boyfriend? because honestly I was feeling a bit jealous and just wanted to see how?d she react.
Her response however is what I?m concerned about. She said along the lines of:
?No I don?t feel that way toward him! Trust me he offered it to me before but I turned it down. He even sent me an unsolicited **** pic in college but I let him know I wasn?t comfortable with that. We?re just friends now.?
This immediately appeared to be a major red flag to me. What purpose does that friendship have if the guy asked you out before and sent you nudes, even if you refused? Would you still be friends with them even after you?re in a relationship? She told me because it was long ago it?s not a big deal, but I feel she has no need to stay in communication with him. What do you all think?
TLDR: Girlfriend drunk called male friend at 2am who previously expressed interest and sent her nudes. I?m not sure how to react.


Source.