On my last flight, a flight attendant approached me before takeoff, in a very soft voice:

"Hello, would you be willing to switch seats so a family can sit together?"
I already know what’s coming. I know it perfectly.
Me: "Which seat is it?"
She: "It’s an aisle seat toward the back."
I tell her: "With pleasure—I’ll help if it’s the same type of seat or better."
She lets out that tight, forced smile of someone who works facing the public and says: "Really, it would mean a lot to them."
I reply: "It also means a lot to me. That’s why I paid for it."
She nodded and walked away. Respectfully, too. Because, what argument was left?