Men, what does it mean when his friends act distant around me?

[Anonymous]

So I've this male friend. Whenever I'm with him, like we're talking to each other one on one or something like that, his male friends would behave a bit different. For clarification, they're my acquaintances too and they usually talk to me when he's not around. But whenever he's around they would just politely acknowledge me and then talk to him. Some won't even do that much. Not much talking, a few words, then they'd just look at him in the eye, smile, shake his hand and go. So I'm curious if it means anything negative.

Updates

3 mo

For those of you that will say: "ask him", I don't need that answer. I can ask him but it doesn't guarantee that he'll be honest with me. So I'm asking for general pov, if you could answer me, I'd be grateful. If you can't, I'm happy nonetheless. Thanks.

[In_Trance]

Just as asking him doesn't guarantee anything, asking complete strangers on the internet does guarantee that nobody knows any more about this than you do

Ask him

[Anonymous]

So he’s your friend and you don’t know but we will?

[Asker]

I'm sorry, I didn't mean to ask girls. I haven't asked him. He's a man and I'm a woman. This is something going on between guys and I don't want to ask him and what's the guarantee that he'd be honest with me? So I was asking for general male opinion. What might be the reason behind such behavior among male friends.