Pete Wentz Parties While Ashlee Simpson Babysits

On the night his wife is booted from Melrose Place, Pete hits the town! Should he have stayed home?

The night Ashlee Simpson-Wentz got booted off Melrose Place, she was busy playing her most important role: mommy!

"She's home with Bronx," Pete Wentz explained of Ashlee's absence from last night's Guess? and Vanity Fair party for the Invisible Children charity.

"He has a 101-degree fever. We're just glad it's not swine flu!" he continued.

The freshly shorn rocker was a cohost at the charity fête along with Kristen Bell and Rachel Bilson—which sort of explains why he wasn't home tucking Bronx into bed or consoling his suddenly unemployed wife. Only that wasn't the only party he hit last night...

Pete also stopped by the Hello Kitty 35th anniversary celebration, where Paris Hilton and her boyfriend Doug Reinhardt were hanging out.

Now, we understand the heiress stepping out to honor the cartoon cat. "Half of my room is covered with Hello Kitty," she told E! News. But was it that important for the Fall Out Boy frontman to delay going home to his wife and kid so that he could attend an extra event?

Survey says: Only if he scored one of the extra-big dolls to take home to Bronx!