Gwen Stefani's older song Kingston turns three on Tuesday, and joined mom onstage at a No Doubt concert so the fans could serenade him with "Happy Birthday" late Monday night.
Wearing protective headphones and sucking a pacifier, Kingston waved to fans before being handed off at the end of the song.
Stefani and husband Gavin Rossdale are also parents to son Zuma, nine months.WATCH:
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