In the car, earlier on, ds1 (18) was describing a crash he had on his bike, at a skate park, when he broke his wrist - and was telling us how many times the word 'fuck' had gone through his mind before he hit the floor. Dh became a tad po-faced about the use of the word, so I may have used it a few times ("Boys - don't say fuck, because dad doesn't like you using the word fuck and thinks it is fucking rude for you to keep on fucking saying the word fuck").
Dh started to tell us, in somewhat pompous tones, how, when he was a lad, out and about in the car with his parents, he wouldn't have dreamt of using That Word in front of them - and suddenly a car nearly pulled out in front of us on the roundabout, almost hitting us, and forcing dh to swerve. Dh shouted, "FUCKWIT", - and the rest of us fell about in helpless fits of laughter at the irony. It took him a while to see the funny side.