simply put it means "who's in charge?". Usually said by superior to their inferior whenever their authority is challenged.
Mom: You're driving way too fast, slow down !
Dad: Hey, who's fucking this cow?
Buy a
who's fucking this cow?
mug!
Female masturbation, enough said.
Jane couldn't get a date for months, so she spent her time home alone, stroking the roadkill.
Buy a
stroking the roadkill
mug!
