What’s the worst fight couples have? Depending on your history with fights in relationships, the question might send a shiver up your spine. I solicited relationship experts of all stripes to reveal the most harrowing fight they commonly hear couples have — that argument that ends the relationship, or at least damages it nearly beyond repair. One conclusion: People say horrible things to each other in fights. Another: There are ways to avoid ever having such destructive fights to begin with. In terms of subject matter, the experts didn’t cite one particular awful fight as most typical, but rather each expert related a different spat they’d heard over and over that clients wish they’d never had. However, though the topic may have varied, the theme was the same: These brawls were down-and-dirty, rough, inconsiderate — and brutal.