Making fun of it, as they would be! (10)
I believe the answer is:
satirising
'making fun of' is the definition.
(I've seen this before)
'it as they would be' is the wordplay.
I cannot quite see how this works, but
'it' could be 'sa' (old-fashioned abbreviation for sex appeal) and 'sa' is found in the answer.
'as' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for satirising that I've seen is " Making fun of".)