|TAI - you don't need this|
The two husbands were TIED together all day - you can't replace one without replacing both of them.
|( を ) か＊える||
I switch from one thing to another thing - usually of a different type: (switch channels / modes / clothes / sides)
|( が ) か＊わる||
something was substituted-something automatically switches (modes/channels/places)
to make change - i.e. "Do you have change for a dollar?"
Two husbands agree about MONEY (i.e. it is awesome)
but every DAY they substitute one for the other in a game of wife-swapping.
Everyone has a HEEL fetish.