He tells her not to wait up, and she says she'll be waiting no matter how long.
I told him that we might be late and not to wait up.
When he brought me home, my father was waiting up for us.
I got back and she was waiting up for me.
He wondered for a second if she had just been waiting up on her high floor.
Old friends would be waiting up for him in the small hours.
It's waiting up there at the end of the river.
"There is no need for both of us to wait up."
"May I write a note to a friend who is waiting up for me?"
Gary was waiting up for Mark when he got home, in the room they used as an office.