Like a cat that’s got the cream
Definition 1 of 1
Pro Tip 1/3Satisfaction Shown
The phrase shows someone is visibly pleased, much like a cat would look after enjoying some cream. 
Winning the debate, he sat back like a cat that’s got the cream.
Pro Tip 2/3Not Literal
It's not about actual cats or cream; it's used metaphorically to describe a person's satisfied expression. 
After the promotion, Laura was like a cat that's got the cream.
Pro Tip 3/3Informal Context
The phrase is informal, best used in casual conversations rather than formal writing or speeches. 
Look at him acting like a cat that’s got the cream, just because he won the game.