Entertainment TV 'DWTS' : Guess Which Big Star Came to Watch Derek Hough Tango? Kate Hudson came to watch her pal tango at Monday's Dancing with the Stars By People Staff Published on April 7, 2015 01:00 AM Share Tweet Pin Email Photo: David Livingston/Getty Demi Moore wasn’t the only big star in the ballroom Monday night at Dancing with the Stars. Kate Hudson grabbed a seat off-camera to watch Derek Hough perform the Argentine tango with Olympian Nastia Liukin, PEOPLE has learned. The 35-year-old actress was able to slip in and out of the Los Angeles soundstage without many people knowing, especially the press, who were assembled backstage. Though she and Hough, 29, have been dogged by rumors that they are dating, a source close to the pro hoofer told PEOPLE the two are “just good friends.” Hough is bi-coastal these days, because he’s splitting time between DWTS – where he and Liukin were the first couple this season to earn three 10s during Monday’s performance – and New York’s Radio City Music Hall, where he’s starring in the Spring Spectacular. Unlike Hudson, Moore was caught on camera cheering for her daughter Rumer Willis, who together with Val Chermkovskiy earned a 35 for her waltz. Behind the Scenes of Dancing with the Stars