DD goes to her DF's every other weekend. He lives with his girlfriend (she was OW and reason we split up). I never say anything bad about her to DD though obviously.
DD once came home when she was about 18 months and said 'mummy bitch' and went through a phase of saying 'I like Louise' (not her real name) and it was clearly taught to her because she never said it about anyone else except her. I just agreed with DD and said 'very good' sort of thing.
She's 2.7 now and hasn't mentioned her for few weeks. Yesterday I asked if she wanted something and she thought I said 'Louise' and then she went really quiet and wouldn't speak to me. I asked what was wrong and she said 'Louise angry with me' and 'been shouting at me' and then she did an impression of someone really shouting and being angry. I didn't want to put words in her mouth so I just asked who said that and she replied 'Louise' and screamed 'you're not my mummy, Louise!' I asked why she said that and she said 'because you're my mummy, she's not my mummy'. I stopped talking about it and changed the subject because I didn't want to push it or force her to tell me more.
Today she said the same sort of things and also said that her dad had gone out on Sunday and that Louise had said 'I don't want you in my house'.
DD does say stuff that isn't true a lot but I don't think she knows what lying is and it's mostly stuff like that she's been to the seaside today or she's had ice cream for tea. Silly stuff usually.
I don't know what to do. If I speak to her dad he will just deny any of it anyway even if he knew she had said it and he will say I'm trying to cause trouble. He's so defensive and turns me innocently asking something into me having a dig which is why I rarely ask him anything or stick my nose into his time with her.
I'm worried now that she might be being horrible to her but I don't want to go accusing her and causing tension.