Company politics aside its the answer that will probably be your best bet. Leaving him in back can't be good, and trying to fake him an upgrade could backfire somehow (let's say another flyer is there to say... hey, if he's not taking it, I am next on the list)

You can't go wrong with sitting in the same class of service, get some face time, and work dilligently on the flight. You can get some "points" by allowing him to board with you in zone 1 (flame-on....).

If he asks you can say you were offered the upgrade but declined it. Then tell him the upgrade grass on the DL side is greener than *A and he should come over as well. Get him the status match info.