Party after working once in a while (2,8)
I believe the answer is:
on occasion
'once in a while' is the definition.
(I've seen this in another clue)
'party after working' is the wordplay.
'party' becomes 'occasion' (I can't justify this - if you can you should believe this answer much more).
'after' says to put letters next to each other.
'working' becomes 'on' (e.g. a machine is working or on).
'occasion' put after 'on' is 'ON OCCASION'.
Can you help me to learn more?
(Another definition for on occasion that I've seen is " Sometimes".)