Ug, Redux

Driving yesterday. Someone ahead of me is having a hard time staying in their lane.
Me (under my breath): “What the fuck…”
Ian: “What the fuck…”
(damn, he wasn’t supposed to hear that, especially from the back seat)
Me: Ian, you shouldn’t say “fuck”. It’s not a word for kids.
Ian: What does it mean, dad?
Me: It’s kind of like shit, Ian.
Ian: Ok, how about “What the ug…”
Me: That works.