It was a parent’s night out for Cameron Diaz and Benji Madden on Saturday, March 23 after surprising the world by announcing the birth of their second baby the day before. Mom and dad took a night off from enjoying their baby boy to join in on a celebration of a different kind — an A-list birthday party.

Diaz, 51, and Madden, 45, were photographed at a party for actor Rob Lowe’s milestone 60th birthday in Santa Barbra, California. The typically private couple kept it casual in all black looks in photos obtained by People Magazine. Diaz sported a simple jacket, shirt and pants combo while carrying a brown box and flower branches in her hands. As usual, she looked fresh-faced and stunning with simple makeup. Madden wore a baseball cap with a black denim jacket.