My Dad and his wife want DD1 to stay overnight and I don't want her to. We have a bit of a troubled relationship which I'll get to in a bit. We have 2 children - DD2 has just turned a year and is a bit of a lockdown baby so has never really left my side so there would be major drama on her part if she was stay with them. DD1 is very comfortable with her grandparents and could stay no bother. They asked me last week if she could come stay and I said no, that she's a sibling (they share a room together) and you can't really take one and not the other and said that when DD2 is a bit older they can both stay.
Now they have come back to me saying they don't understand my logic. So, here's the background. Firstly I feel that they treat DD1 and DD2 differently. I think they blame it on DD2 being a baby and not seeing her much due to lockdown so they haven't got to know her as much. But when we are all together they are so enraptured by DD1 that DD2 doesn't get as much attention. When DD1 was a baby they were all over her but DD2 is left to get on with it. Even things like food, they give DD1 food then ask about DD2 like she's an afterthought. Letting DD1 stay over would just cement this different treatment. Also, DD1 is nearly 3 now and I wonder what it would say to her that only she goes to gran and grandads and not her sister. It very much feels like DD1 is a grandchild and DD2 is by default.
I don't have a great relationship with them myself. We get on but this is due to considerable effort on my part in keeping the peace - I don't let rip. I feel as though my Dad only tolerates me in order to keep seeing his grandaughter. He often falls out with me, he doesn't say so, he just ignores me for a few days then messages again. He's only finished ignoring me because he reccommended a movie - I said if it included children being hurt then I'm out because I can't watch things like that anymore - I wasn't rude or cheeky and only said it because the last time he recommended a movie it had children dying in a house fire. So he took the huff ane ignored me for about a week. He came back saying he hadn't been in touch because he was hurt?!?! It was ridiculous that anyone could be offended!! Then he was in touch to ask if DD1 can stay. In terms of a supportive loving father - he helps me now and again with money which I am very appreciative of, but that's all I get. He can barely have a conversation with me and I find talking to him extremely difficult as he is so judgemental. I am reluctant to allow DD1 and DD2 get so close as I don't know how he'll be with them when they get older. If it's like how he is with me then I'd rather they never saw him.
I find the whole thing awkward - I don't know what to say to them. Am I right that they should only go as a pair? Is there anyway I can back up this angle to keep him at bay? Any advice on what to say back?
(We're in scotland and they are in our extended household)