the moment during a devil's three way when the two guys bump fists over the chick's back while she's giving head to one guy and the other guy is riding doggy style.
whist jimmy and stan acknowledged that whilst there was too much penis in the room for either of their likings, the devil's fist bump made the experience totally worth it.
When you're engaged in sexual intercourse, typically in the doggystyle position, and you fuck so hard that your hipbones are hitting her assbones to the point of physical pain.
"shit dude i was hittin the bump stops in that $1.20, it was a mercy root i swear"
"Man I was smackin the guts out of the missus last night, goin so hard i hit the bump stops"