Nuts & bolts!
They're both filled with nuts
She is allergic to nuts.
Stop being a centipede." Get it, because the robot has no arms! Hahhahaha, gets me everytime.
Nut and bolt
When they find the position, they can't find the momentum. When they find the momentum, they can't find the position.
They're shellfish in bed.
They don't really know - but they're NUTS about him!