Both kids insisted that they want to get ready for bed last.
I told Vian (4yo) in secret that we're going to trick Sempi (8yo). He should floss and brush but not do MiPaste (a Fluoride paste). Then after I get Sempi ready we can do MiPaste, Vian would be the last to get ready.
Vian bought into the idea and he brushed first with a mischievous glee. The plan worked like a charm, Sempi was happy that he was brushing after Vian and Vian was happy that he didn't do his MiPaste until after Sempi brushed, thus he was the last to get ready for bed.
I emerged the victor.