Pet's routine badly affected (11)
I believe the answer is:
pretentious
'affected' is the definition.
(I've seen this before)
'pet's routine badly' is the wordplay.
'badly' indicates an anagram.
'pets'+'routine'='petsroutine'
'petsroutine' anagrammed gives 'PRETENTIOUS'.
(Other definitions for pretentious that I've seen before include "trying to impress" , "Pompous, self-important" , "Foolishly grandiose" , "Affected" , "Arrogant" .)