Gwen Stefani and country star Blake Shelton were among the host of famous faces who took part in big-budget TV commercials during the Super Bowl last night.In the T-mobile advert, Stefani offers a not-so-serious look at how she first became romantically involved with Shelton – after the pair announced their engagement last year.The clip sees Stefani on a video call with fellow The Voice judge Adam Levine, explaining that she’s ready to get back into dating.“I’m sick of L.A.