Julianne Hough's ex-husband Brooks Laich rang in his 37th birthday this Tuesday with her brother Derek Hough.As seen on both Brooks and Derek's Insta Stories, the two hunks worked up a sweat with a strenuous workout session in a garage.They were joined by Derek's girlfriend Hayley Erbert as well as their pals Kristy Sowin and photographer Cory Tran, who is engaged to Freida Pinto.