Put/stick two fingers up at somebody
Definition 1 of 1
Pro Tip 1/3Offensive Gesture
This is a rude action, similar to the middle finger in the US, and may upset people. 
He stuck two fingers up at the rival fans, causing an uproar.
Pro Tip 2/3Cultural Specific
Primarily understood and used in the UK and some Commonwealth countries, not globally. 
When she moved to the UK, she learned sticking two fingers up had a different meaning there.
Pro Tip 3/3Anger or Disrespect
Expresses strong negative feelings; avoid using it unless you want to show anger or scorn. 
After being insulted, he responded by sticking two fingers up and storming off.