feather (your) (own) nest

to make a lot of money for yourself.

While the CEO feathered his own nest, his company was firing employees by the hundreds.

Usage notes: usually said about someone who takes unfair advantage of others

Related vocabulary: line your own pockets

• a shot in the arm
• a shot in the dark
• a shoulder to cry on
• a shouting match
• a show-stopper
• a shrinking violet
• aside from
• aside from something
• a siege mentality
• as if own the place
• as if you own the place
• a sight for sore eyes
• a significant other
• a sign of the times
• a sine qua non
• a sinking feeling
• a sinking ship
• a sin tax
• as it comes
• as it stands
• a sitting duck
• a skeleton in closet
• a skeleton in cupboard
• a skeleton in someone's closet
• a skeleton in the closet