Looking offended by power trip (7)

I believe the answer is:

pouting

'looking offended' is the definition.
(someone who is upset or offended might pout)

'power trip' is the wordplay.
'power' becomes 'p'.
'trip' becomes 'outing' (I've seen this before).
'p'+'outing'='POUTING'

'by' is the link.

(Another definition for pouting that I've seen is " Expressing displeasure with the lips".)

I've seen this clue in The Guardian.

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