Student or Learner
When traveling by plane, the stewardess always warns to "fasten your seat belt" and "remain seated" during the take off and landing of the aircraft. Can I use the expression "remain seated" in other contexts or is it aviation jargon, please? For example, can I say "Son, remain seated until the doctor comes, will you?".
When you're talking to only one person, you say "keep your seat."
"Remain seated" sounds most natural when you're talking to a great many people.
It's customary at a wedding for the guests to remain seated until the wedding party has exited the sanctuary.