I'm from the UK where guys love to fight after a few drinks.

One thing I always struggle with is when a guy says something or makes a comment thats trying to put me down in some way. Now 80% of the time its just playful and easy to deal with. But the other times they say something that I feel like I need to address and basically say that I'm not going to stand for someone talking to me like that.

The problem I find is that when a guy makes a comment like that, normally in front of his or my friends, and I tell him how it is, they almost always get violent. They dont want to lose face in front of people and just escalate it to "why dont we go outside then?".

I'm not worried about fighting since I do a lot of martial arts anyways, but I dont want to street fight. Its silly. So I just dont know how to handle these situations.

Perfect example, last night waiting to get in to a club. Me and a female friend are teasing eachother, just playful flirting. This guy in front joking says something to the tone of "nights only just starting and we already have a little domestic case on the go". I laugh and make a joke back, nothing major.

Then he looks at my female friend and says in a very serious tone "if I was you I'd take him outside, kick the shit out of him and leave him".

Now obviously this is an extreme case. What I wanted to do was basically make fun of how hard he was trying to whiteknight the girl. Something like "wow this guy is trying his hardest to get laid tonight isn't he". But I just left it and kept my cool and everything was fine, but it did really annoy me and I felt like I should have told this guy where the line was, but I could tell he would have happily had a fight with me to save face.

TL:DR - How do you tell a guy that the way they are acting or what they have said has crossed the line and annoyed you and that they need to stop, without them instantly just escalating to physical violence?

I feel like theres an alpha way to firmly put your foot down with this kind of bullshit.