I professionally translate/adapt dialogue for plays, movie scripts, TV shows and the like from X language into English. I confess that whenever I get to the argument bits, I always pepper the text with witty one liners and fleeting expletives from (in some cases, decades' old) fights between me and all my exes, and from bitter-turned-comical spats my mum and dad used to get in. My late gutter-tongued aunt also is a source of inspiration when words fail me. I do so largely for the sake of flow, authenticity, and naturality when the context calls for it. And trust me, the material is as juicy and colourful as one can get, not to mention seemingly bottomless. Makes for fantastic therapy. :-)