Think of all the times you've said those things yourself, usually in a tone of mild or serious frustration.

Garbeck cast a look of mild frustration in Shelby's direction, and Shelby certainly understood it.

He blew out his breath in mild frustration.

Grundy heard the angry ogress mutter in mild frustration as she moved away.

The expression on her face went from pure ecstasy to one of mild frustration.

Xabbu shook his head in mild frustration.

It was with a sense of mild frustration that he pulled the sensors back into their recesses.

Sighing in mild frustration, he added, "Bit of a vicious circle, isn't it?"

Miles stared across the gap in mild frustration.

Spock let out what would have sounded like a sigh of mild frustration in a human.