Mom's night out!
took a night off from baby duty with 19-month-old Luca Cruz
to support fellow former Disney darling Selena Gomez
at the Los Angeles stop of her "Stars Dance"
tour Tuesday night.
The actress, 26, rolled into the Freshtops VIP lounge at the Staples Center with eight girlfriends at the start of the show, and the group of gal pals settled into a corner table, drinking wine and cocktails (a favorite was the "Selena-rita," which included sweet watermelon), an onlooker tells PEOPLE.
After going backstage with hairstylists Riawna Capri and Nikki Lee to say hello to Gomez after the concert, Duff and her group of friends returned to the lounge to dance the night away.
"She kicked off her heels," says the source. "She was having a blast and was taking full advantage of her night off from mommy duty."