DS is 5. A few weeks ago at dinner, he suddenly came out with 'we don't say fuck it?' DH and I were a bit taken aback and DS looked quite concerned, as though he knew it was a bad word. We said 'we don't say that' and moved on. A few days later he asked again and again and again. The question/statement has now morphed to 'I won't say fuck it again' or 'fuck it is not coming back again' but this has become constant.
I've tried replying calmly, he just keeps saying it. I've tried ignoring him, he just keeps saying it. I've gotten angry at which point he gets very distressed. He says it's in his head and he can't stop it and begs me to forgive him.
This only seems to happen around DH and I. It doesn't happen with school or grandparents, though tonight at my MIL's he kept saying it quietly to me and getting upset. Then in the car on the way home, it changed to 'we don't say fat, do we?' Again, this was constant.
I don't know what to do. DH thinks he's putting it on to wind is up, but I don't think he is given his distress. Could it be some kind of Tourette's? I just don't know what to think or do.