spoil somebody rotten

do somebody wrong

To treat someone badly or unfairly.

rotten apple

A bad person, especially one who has a corrupting influence on others.

rotten egg

A person who is the latest, the last, or the slowest in a group to arrive somewhere or to perform a certain task.

something is rotten in the state of Denmark

Something is not right, seriously amiss, especially when leading to suspicion of motive.

spoil market

Alternative form of spoil the market.

spoil someone rotten

To overindulge someone, especially when it results in making them selfish and demanding.

spoil the market

To set higher standards by overachieving, so others look inferior or unmotivated in comparison.