Dun dun dun! We've heard rumors that these two were on the rocks for quite some time now, but we certainly haven't seen them do something like this before!

Last night, Deryck Whibley and some male pals arrived at MyHouse around midnight, and he left around 12:50am. When asked where his wifey was, the Sum 41 frontman remained totally silent. Normally we'd just leave it at that, but guess who showed up within minutes of Deryck's departure?

Yup, just before 1am, Avril Lavigne traipsed right into the Hollywood hotspot with...Brandon Davis?! Ew! And that's not even the worst part - our photographers spotted Avril sitting in his LAP when they left in a limo later.

We're not sure why Deryck and Avril would go to the same club at different times, but Avril hanging out with Brandon Davis? I know he's a mutual friend of both Paris and Av, but if I was Deryck, I'd be livid!

Think they're headed towards divorce, or did Deryck simply need a night away from his lady?