Given that all of the women I have been regularly intimate with have liked it somewhat rough, I found the phrase "beating on each other" suitable, though at least the vast majority of "beating" has always been done with genitals.
pick up a hooker and take her for a little ride
but get sucked off on the side
sworn to serve and protect, forget the killing
badge-wearing fascist villain
pissed in the street, you bust the guy
do you like to see his children cry
-Poison Idea (later Pantera)