My son refuses to sleep over at mil and sil’s house. He’s 7, he doesn’t mind going over there in the daytime for a few hours but will not spend the night. When we go over for a visit mil and sil always bring up about staying the night, he says no straight away and then they keep on asking why and then try and bribe him to stay by telling him we’ll buy you whatever you want if you stay he says yes but as soon as we get home he starts to get upset saying he doesn’t want to go. I feel bad because they’ve bought him a bed and this stuff to stay there as he says yes when he’s there but as soon as he comes home he’s adamant he’s not staying. He’s getting really upset by this. I’ve told him I’m happy for him to spend the night and it’s his choice. My partner wants to force him to go but I can’t force him as I know he’ll be so upset. What’s the best way to deal with this situation