sweeten (up) the kitty

To make something more enticing, alluring, or attractive, especially from a financial perspective. He was still unsure whether he wanted the job, so the company offered to sweeten the kitty with an excellent pension plan. Don't be afraid to sweeten the kitty with a little bit of pocket money if your kids are really unwilling to do chores.

Also, sweeten the pot or deal . Make something financially more attractive, as in I am unable to give you the new title but I could sweeten the kitty a little by giving you a raise . This idiom comes from card games such as poker, where it means "add money to the pool," and uses sweeten in the sense of "make more agreeable." [Slang; c. 1900]