I feel like this kind of social play-wrestling is the holy grail of peer-to-peer interaction that has eluded me. I'm competent at one on one small talk, group settings, formal events, casual, but when it comes to knowing when it is and is not okay to switch into 'insults mean I value you as a friend' mode, I am completely at a loss.

For example, friend A says to friend B, "hey buddy, you look like a prepubescent walrus pup with that shaggy-ass porn stache you got there". Clearly this is an insult against friend B's terrible mustache, but it comes across as funny, true, loving, and helpful rather than mean, vindictive and petty as the literal words imply. Other similar behaviors are: flipping each other off as a gestural greeting, answering phone calls with a belligerent "fuck you", and belittling one another's penis size and sexual prowess.

I know I sound like an alien trying to analyze interpersonal human behavior, and that's exactly how I feel, but could somebody give me a hand understanding this kind of play? I feel like giving up social interactions because banter is just so exhausting and unnatural. It's one reason I tell people I spend most of my time alone because I don't understand banter.