It's not often that the both of them are completely out of clean laundry, but the fact is that on this occasion they were both extremely busy at the same time and it didn't click that the other one wasn't doing laundry either until both their closets were bare. Aaaaaaand it's almost two in the morning. 

And this is what leads to a pair of twins hauling an enormous laundry bag to an all-night laundry in the wee hours of the night.