Universal's terms have varied over time, but booking up to two rooms under the AP rate has generally been permitted. If you're booking online and the system allows you to reserve both rooms at the AP rate, that's usually a good sign. I have done it with my son and his girlfriend in the exact same situation, and they never asked me anything. They didn't even make me put my name on the room.
At the end of the day, 99% of the people behind the desk don’t care; they just want to confirm you are who you say you are and move on to the next guest.