Canadian chart-topper Avril Lavigne is at war with SUM 41's STEVE JOCZ over an underwear-pulling prank, and promises there'll be "payback".

The 19-year-old COMPLICATED hitmaker is currently dating the pop-punk band's frontman DERYCK WHIBLEY - but is in the middle of a "wedgie" feud with his drummer bandmate.

She says, "I gave Steve from SUM 41 a wedgie, but he also claims he gave me the biggest wedgie he's ever given anyone - which is incorrect information and I'm gonna get him back large.

"We were hanging out in New York and I walked over to him and nearly ripped his boxers off, so it all started there. But there'll be payback."

13/08/2004 17:35