Over the past week my 2.9 yo DS has picked up a swear word, I'm not sure where from exactly and it could have been from me. I've spoken to all family members about it and everyone has agreed to stop swearing around him - I don't think they realised that he was even listening before now. I'm very ashamed so please don't make me feel worse than I already do, but I need some tips on how I deal with this so that he's not the child who is swearing at everyone at nursery.
The contexts he's said it in are: once when he was frustrated and twice when he was doing something he knew I'd tell him off for. The first time he used it I ignored him completely, I thought he'd forgotten but then he said it again today. I tried to tell him he'd got the words wrong and gave him an alternative which he repeated, laughed at and then said the original swear word again.
I considered telling him it was naughty but he tends to do 'naughty' things deliberately to get my attention. He's been acting out a lot since his baby brother was born a few weeks ago so meltdowns are commonplace. He's repeating everything, including all of the phrases I've been using with him to deal with his behaviour, so I worry that if he knows it's naughty he'll just keep saying it.
Do I just completely ignore it and hope it will go away on it's own? Or do I do something? I'm so worried that I reinforce it and he continues to say it. I'm really ashamed and every time he says it I want to cry.