THERE’S a new gay power couple on Broadway. Jonathan Groff, who was nominated for a Tony for his work in “Spring Awakening,” has been dating “Hair” star Gavin Creel, a source tells Page Six. Incidentally, Creel, who plays Claude in the musical, took over the role from Groff, who initially starred in the revival when it opened last year. Groff will also soon appear in a guest run on Fox’s “Glee.” Reps for the actors didn’t get back to us.