ashleepetebigd2911.jpgAshlee Simpson and her rocker hubby Pete Wentz are calling it quits. Jessica's younger sis filed divorce papers just this morning.

In the papers, Simpson cites "irreconcilable differences" as the reason for the split. Ashlee is asking for joint legal custody and primary physical custody of their 2-year-old son Bronx.

X17online captured the last photos of the couple together last Friday when they hit up a local Starbucks. Over the weekend, Pete headed to Dallas by himself for the Super Bowl while Ashlee stayed home to party in LA.

Our photographer who took the photos at Starbucks tells us exclusively:

    "There was absolutely no sign of trouble between them. As they were walking back to their car, they were totally lovey dovey and talking really close to each other. This is a complete surprise. Didn't see this coming."

Simpson is asking for child and spousal support. The couple, who reportedly do not have a prenup, tied the knot on May 17, 2008.