'Hills' Goss: Brody And Avril Get Inked With F-Bombs?!

Nearly a month ago, Brody Jenner and Avril Lavigne made a permanent mark on their relationship by getting matching lightning bolt tattoos. Well, apparently the light was starting to dim because RadarOnline.com says the couple not only went to get ANOTHER set of matching tats, but this time they went for something more R-rated.

A source told RadarOnline.com that Brody and Avril asked the parlor to ink the word 'F**K' on their ribs. "Neither of them seemed to stop and think about what they were doing. It was just one big laugh."

We'd sure love to get to the bottom of this rumor ... so if anyone spots the couple lounging poolside, let us know if they're all "f**k"-ed up.