Hmmm... I see 'conflict' falling into three categories: fighting, arguing, & squabbling.

Fighting is physical, & I'm with pretty much everyone else here on this: they never do it when they're angry at each other. They do fight on a regular basis, but that's sparring, & it's more a bonding exercise than anything else. It can occasionally look vicious to outsiders (I can just see someone calling up Coulson early on, saying 'come to the gym, Hawkeye & Black Widow are trying to kill each other'), but for those in the know, it often draws an admiring crowd for the show. They might occasionally do it when one of them has the irrits or angry with someone else, & needs to blow off steam or work off a bad mood, but again, for them this is the equivalent of one person holding the punching bag while the other beats it up. They don't hold back from each other in physical conflict (other than the obvious 'it's a bad idea to cause damage to your partner when you might get called into action at any time') because they know exactly how the other fights, & how far they need to be pushed at that moment; in some ways, it's an ongoing show of respect; 'I know I'm awesome at what I do & I'm perfectly aware that you're awesome enough to keep up with me'.

Arguing is strictly verbal, & it's done coldly & calmly. They mostly do it quietly & by strict codes of war, because again, they are acutely aware of how much damage they can do to each other. Arguing happens over serious issues, & unless there's an unexpected call to action, they don't stop until either one of them needs a breather to get their thoughts in order (and for that, they don't go further than the balcony or next room) or the issue is resolved. Partly because they know how precarious their lives can be & unresolved issues & regrets aren't things that should linger with people who are important to them, partly because lingering issues that could lead to work problems are something they can't afford in the field, because their lives often depend on each other.
Something comes up in the field (which became very rare after the first year or so) it's always 'We're busy, so just do this & this because it's necessary, & we'll discuss this when we get back'. First & foremost, Clint & Nat are professionals
I don't see arguing as happening very often, because let's face it, when your life is this intricately involved with someone (I'm talking about straight partnership, no romantic involvement at all) if you don't genuninely get along you don't last very long as a pair, & you certainly don't pull off the kinds of stuff that it's obvious Clint & Natasha have unless you're in sync - which again, doesn't happen if you don't agree on things most of the time anyway.

Squabbling, on the other hand, is not only verbal, but heated. It's for the day-to-day shit, stuff which they each step around most of the time anyway - or just because they're bored! It's more banter than anything else, mostly, but banter between two very dangerous (but never to each other) people.
Sarcasm & inventive insults (especially in other languages) is not only encouraged, it's expected, & they'll sometimes give compliments or even rewards afterward for the best line.
It sometimes happens on missions (especially over comms!), but it's basically the equivalent of two cops giving each other shit over coffee on a stakeout, & only when they're in a solid place personally. When they were all still in the field, Coulson would occasionally interject a comment or two over the comms as well.
When they squabble at home, they tend to squabble to a standstill ("Fine, then!" "Fine!") & work off the pent-up energy with jungle sex. Or they'll occasionally play-fight (rough & tumble wrestling, but no hitting!) until it turns into 'aha! victory is mine! Now you have to give up the remote/clean all my equipment/be my love slave for the rest of the night!'.
(Clint has been known to say things like 'I have you now, my pretty!' Natasha will use phrases like 'Get naked, American scum, and bring me chocolate icecream. I'll decide whether you're worthy to be used as my sexual plaything after you rub my feet.')
(oh, crap, is that a plotbunny I hear hopping towards me?)

Edited 2012-12-23 04:58 am (UTC)

Excellent categorizations. Very nice!

And happy plot bunnies are happy! And they spawn MORE plot bunnies (b/c rabbits are like that.) :D