Who would you believe in this situation?

So kids aren’t stupid..

They copy behaviour.

My ex has always hidden from me the fact he smoked. When we was first together yes I knew he did it. I absolutely hate it and told him to stop. He said he had and two years into our relationship I was still finding them and seeing he was buying them on receipts. He’d tell me they weren’t his, buying for friends and all that rubbish. He’s promise me he’s stopped.

Anyway fast forward and 5 years later we have a 7yo and 2 1/2yo and my older child has told me several times over the years she’s seen him do it.

Still he tells me she is making it up and he doesn’t.

So yesterday my 2 1/2yo put a pencil between his fingers and lifted it up to his mouth and said ‘look Mummy!’

I said who does that, for him to reply ‘Daddy!’

Now I am furious.

1) because he is STILL lying to me. Yes before people start I know we’re not together and he can do what he likes, but when he has previously sworn on our children’s life and promises me he has stopped - I do not appreciate that.

2) he is saying my 2yo doesn’t know what that is and basically done this randomly! Kids are not stupid. I said to him this behaviour has been copied and for him to say ‘Daddy’, you can’t even argue!

3) he is doing it clearly in front of my children!

Would you believe a 2 1/2yo in this situation..

-*when I say smokes, I mean normal cigarettes.. not anything more!