Desert Italian abroad? Don't do that (5,2,3)
I believe the answer is:
leave it out
'don't do that' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'desert italian abroad?' is the wordplay.
'desert' becomes 'leave' (desert can mean to leave or abandon).
'italian' becomes 'it' (abbreviation for Italian).
'abroad?' becomes 'out' (abroad can mean away or out).
'leave'+'it'+'out'='LEAVE IT OUT'
Can you help me to learn more?
(Another definition for leave it out that I've seen is " Stop it!; Don't mess about! (inf)".)