The exes split in 2015, and the No Doubt frontwoman married her Voice co-star six years later.

Gwen Stefani and Gavin Rossdale attend the PEOPLE Magazine Awards at The Beverly Hilton Hotel on December 18, 2014 in Beverly Hills, California. Chris Polk/PMA2014/Getty Images for dcp

After all that they’ve been through, Gwen Stefani and Gavin Rossdale are cool — at least, cool enough to reunite to support their son Kingston at his recent concert, with the No Doubt frontwoman attending with husband Blake Shelton at her side.

The three musicians were all in the audience Tuesday night at The Troubadour in West Hollywood, California, as Stefani and Rossdale’s eldest son rocked out onstage, according to photos circulating online.…