Mordecai and Rigby couldn't bend over to tie their shoes without setting off the apocalypse, the fact that they swapped with Their significant others at the time pretty tame all things considered, the swapp happened because Mordecai was drafted to babysit Death's kid yet again and the Brat thought it would be funny to swap them
This would of made a neat story/fanfiction/episode. Just wished that Mordecai and CJ would of been the ones to marry in the end...
Swap mordecai and rigby with ponys !!! Remember no Ponys allowed in The park
Now that would be an interesting situation, especially female ones from the MLP Friendship is Magic series.