pinniped

I don't think I've ever been a total d*ck onboard. There have been a handful of cases where someone has tried to seat-swap with me in what I considered a suboptimal manner, and I stood my ground, told them to beat it, and even offered advice on how they should have approached the seat-swap to begin with. I may have been a wee bit condescending but dammit, I was right, they were wrong, and their piggishness invited the exchange.

(FWIW, usually a variant of swapper hoping that swappee accepts a worse seat, instead of swapper with better seat offering to accept lesser seat in exchange for sitting together. If you're holding 8B and 29A, you should be talking to 29B, not 8A.)