Crossword puzzle clue "when a man is nervous about shipping breakables i tell him ' carefully sir'"

"When a man is nervous about shipping breakables, I tell him, '___ carefully, sir' ..."

Means of protecting breakables

Rocker Case who tweeted "If a dude called me a 'cougar' I'd be more likely to kill him bare-handed and shit him out in front of his parents than fuck him"

"Yes, sir, captain, sir!"

Sir Samuel Cunard and Sir Henry Royce

"Yes, sir! Right away, sir!"

To whom a private says "Sir, yes, sir!"

How to tell Pac-Man from Ms. Pac-Man