He wasn't objecting at all. In fact, he was the one that suggested that he rent a tux because he knew his dad was going to get fitted for one.
I told him no tux, but that he should wear his suit and could ditch the jacket after dinner and pics. He said that once onboard he'd ask the other kids if they were going to change back into normal clothes after dinner and whatever they did, he'd do the same.
P.S. Thanks Fern for the link to the teen board.