Tricking, slyly, all up feasting on bananas (7,1,4,3)

I believe the answer is:

pulling a fast one

'tricking slyly' is the definition.

'all up feasting on bananas' is the wordplay.
'bananas' is an anagram indicator (informal term for mad).
'all'+'up'+'feasting'+'on'='allupfeastingon'
'allupfeastingon' anagrammed gives 'PULLING A FAST ONE'.

I've seen this clue in The Telegraph.

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