Article continues below advertisementChrishell Stause isn't afraid to tell Gwen Stefani how she feels. The Selling Sunset star, 44, is a bit miffed over the No Doubt singer, 56, collaborating with prayer app Hallow. "Gwen-DON'T SPEAK," Stause commented on an Instagram Reel that featured the ad with Stefani.Article continues below advertisementGwen Stefani Urges Fans to Download Hallow This ChristmasSource: MEGAGwen Stefani is partnering with Hallow this holiday season."Please take your own advice on this one🫠," the comment continued.