My (23m) girlfriend (23f) “accidentally” fell asleep cuddling her guy friend in his bed and didn’t reply to my phone calls until 3am, what should I do?

Last Friday, my girlfriend told me she was going out with a few friends. We don't always go out together so this wasn't unusual for her to do and I've never had a problem with it until now. So, later on that night her messages became less and less frequent until they stopped altogther. At this point I was slightly concerned, but again I trust her so I left it for an hour or so presuming she was just having a good night. A couple hours had passed and it was 3am and there was still no answer. So I called her to see if she was okay and/or coming home soon. Again no answer. I called her twice more…no answer. The fourth time, she picked up already in the uber home. I asked her where she'd been and she said she'd been at her male friend's place we will call Harry. Harry (25m) has been friends with my GF since they met at work 3 or so years ago. They've always been close but she has assured me they have never and would never hook up. The few times I've hung out with them they seem friendly but I've never been too concerned with their relationship. Anyway, when she got home I tried to ask her about her night but she was too intoxicated and passed out in bed. The next day, I asked her again about her night and she told me she never ended up going out and instead went over to Harry's house for some drinks. I asked if a couple of her other usual friends went too, but no, it was just her and Harry. I then asked her why it took so long for her to get back to me and why was she at his house so late in the first place. Throughout the discussion, it came out that she had fallen asleep cuddling him in his bed, but to not worry about it because he's just a friend, nothing happened and I should just stop overthinking all the time, completely dismissing my concerns. Now I'm at work not knowing what to do or think. Is she right, am I just overthinking and they're just friends, or am I right in feeling uneasy about her falling asleep in another guy's bed, or worse if something else happened?