Don't mention mounted trophy I've ordered paramour (4,1,4,4)
I believe the answer is:
draw a veil over
'don't mention' is the definition.
'mounted trophy i've ordered paramour' is the wordplay.
'mounted' shows that the letters should be reversed in order.
'trophy' becomes 'award' (I've seen this before).
'ordered' indicates anagramming the letters.
'paramour' becomes 'lover' (I've seen this before).
'award' back-to-front is 'drawa'.
'ive' anagrammed gives 'vei'.
'drawa'+'vei'+'lover'='DRAW A VEIL OVER'
(Other definitions for draw a veil over that I've seen before include "Be discreet about" , "Refrain from mentioning" , "hide" , "Avoid calling attention to something" , "Avoid discussing (an unpleasant thing)" .)