low key long

Low key long describes something that's technically manageable but quietly, persistently draining in a way you don't fully register until it's too late. You don't complain about it in the moment, you don't even consciously clock it — but afterward you're inexplicably exhausted. That lunch that stretched two hours without any single bad moment. The text conversation that somehow never ended. Low key long sneaks up on you, and you only identify it in hindsight when you're lying on the sofa wondering where your afternoon went.