Quick background. I have 1 DS 9, we live with DP and his eldest DD 10, and we have his other two DD, 7 and 3, every weekend from thursday/friday to sunday.
The 3 year old had her birthday last month. I put my foot down and took the executive decision to try toilet training her. Every time before that, I mentioned it to DP he said it was up to his XW to sort it as the resident parent. So one day I just put her in some old knickers and let her run round outside in a dress. She got a bit upset when she wet herself, but over the next couple of weekends she began to get the hang of it. You can tell when she needs to go, because she kind of holds herself down there. At night and when we go out we put nappy pants on her and then she doesn't ask for the toilet, but in knickers she does.
DP told XW that she won't ask for the toilet when in nappy pants, but she has made no effort whatsoever to toilet train her, despite the fact that she only works part time and has every weekend child free, while both DP and I work full time and are exhausted most of the time, we still make the effort.
Am I BU to be frustrated and annoyed at this woman?