For the Battle of the Sexes

You find a box in the attic.

What’s in the box looks like a radar gun.  It takes ordinary batteries.  If the gun is turned on and the trigger is pressed, then those in the line of fire will experience all of the secondary symptoms of premenstrual syndrome (cramps, headache, irritability, et cetera).

This device only works when used on men.  Keep out of reach of women.