Even though Ashlee Simpson and Pete Wentz didn't work out as a couple, they sure know how to make things work as parents!
Ashlee and Pete reunited to celebrate their son Bronx Mowgli's 4th birthday on Tuesday with a superhero-themed party at The Coop in Studio City.
And it was quite the affair!
Nicole Richie, her daughter Harlow, Simpson's parents and even Wentz's 24-year-old girlfriend Megan Camper showed up for the b-day bash.
According to reports, Ashlee and Pete seemed totally at ease during the party, but the same can't be said for her parents Joe and Tina Simpson ... who arrived separately.
Missing from Bronx's birthday party pics were Jessica Simpson, Eric Johnson and their newest family addition, daughter Maxwell. Ashlee's boyfriend Vincent Piazza was nowhere to be seen as well.
Overall, it looked like everyone had a pretty good time. Click “Launch Gallery” above to see more shots from the bash!