Pull the trigger (on something) phrase
To make a final choice or judgement after thinking and talking about what is the best thing to do, or to stay with and completely support a particular course of action (about something).
There is no time left to sit on the fence - you have to pull the trigger on whose side you're on.
I will consult an expert before pulling the trigger on how to proceed.
He couldn't sway me with his arguments, so I still pulled the trigger on the deal.
The verb "pull" must be conjugated according to its tense.
The origin of this phrase is not clear.