Kick (one) when (one) is down informal verb phrase
To criticize, exploit, insult someone when they are in a weak position.
James has just got fired, so you shouldn't kick him when he's down.
I don't like my boss. He always kick his competitors when they're down.
Instead of helping Jimmy find his wallet, Jack kicked Jimmy when he's down.
Someone who ruins others' fun and enjoyment
The verb "kick" should be conjugated according to its tense.
At a much higher level than other people or things
Peter is head and shoulders above the other contestants in the competition.