Genuinely don't know.
Ds frequently sleeps at my parents because my mum takes ds to school when I have to leave at 640 in the morning for uni. (We used to live with my parents if that had any bearing on this) it is only ever done as a necessity on a school night.
Ds's other grandparents have requested to have him on a school night and then return him before school. (they have him most Friday nights already)
I want to say no, as I have always said no to school day sleep overs unless necessary but I'm not sure if Iabu seen as ds sometimes stays at my parents.