Riley is used by Victoria to help Victoria to gather new borns to attack Bella. Victoria never loved him because she loved James still that Edward killed. Victoria was going to kill Bella to make it even. Bella was protected though by the Cullens, so if Victoria wanted to do anything Alice would see. Alice wouldn't have focused on Riley because she was warned of Victoria instead. Victoria basically told Riley that she loved him while she was just wanting to be able to kill Bella.