How do you handle interservice rivalry that goes beyond the the normal good-natured variety? When does it cross a line?

When it becomes insulting instead of just an exchange of humor. I respect all My bothers and sisters in all the branches of the Armed Forces. I expect each of us will take pride in our own service, its shouldn't be any other way. Just remember though each of us has an important job to do in the service of our country and We may offer small jokes to each other in showing that but let it go beyond that and keep it to a very small limit if at all.

Honestly I've never dealt with any line crossing amongst my fellow service members. But typically you can tell the difference between someone pulling your leg and flat out trying to denigrate you. It also depends on the pre-existing relationship between the two parties. When we're close to people personally, we tend to push buttons harder than we do with complete strangers because we know how our friends will respond.

So while my friends and I can goad each other calling one another a "POG-ass Boot Bitch" and still laugh about it and be friends, if I said that to a complete stranger, they'd most likely take that as insulting.

If you believe someone has crossed the line, let them know. If it truly was a friendly ribbing, they'll probably apologize. But there are people who do thrive on being mean and cruel who will just say "it's all in good fun" or something along those lines and continue trying to provoke people.

It only ever crosses the line for me when people say stupid shit like (and yeah, I've seen it here) 'the Navy isn't a combat service'. Because someone stupid enough to say that is dumb enough to believe it. Otherwise, I'm fully prepared to let the gamut of Sailor insults (squid, swabbie, etc) bounce right off my thick skin, because I'll give as good as I get, and it's just friggin camaraderie.