Everyone I set up and make fun of becomes uncomfortable (3,2,4)
I believe the answer is:
ill at ease
'uncomfortable' is the definition.
(being ill at ease is being uncomfortable or uneasy)
'everyone i set up and make fun of' is the wordplay.
'everyone' becomes 'all' (all people).
'set up' says the letters should be written backwards (in a down clue, letters go up).
'and' says to put letters next to each other.
'make fun of' becomes 'tease' (I've seen this before).
'all'+'i'='alli'
'alli' back-to-front is 'illa'.
'illa'+'tease'='ILL-AT-EASE'
'becomes' is the link.
(Other definitions for ill at ease that I've seen before include "Unsettled, anxious" , "awkward" , "appear uncomfortable" , "discomfited" , "Embarrassed" .)