Gwen Stefani and Blake Shelton have been together since 2015.John Shearer/Getty Images for ACMThere's one thing that Blake Shelton does daily that helps keep his marriage with Gwen Stefani strong."The thing about Blake is that you'll never get through a day without laughing," Stefani said on "The Jennifer Hudson Show."Laughter can help reduce stress, form bonds with others, and even improve health.Gwen Stefani and Blake Shelton have been together since 2015, and there's one thing that he does every day that reminds her why she fell in love with him."The thing about Blake is that you'll never get through a day without laughing," Stefani told Jennifer Hudson on the October 2 episode of "The Jennifer Hudson Show.""You know what I mean?