Fans the flames of old lover with super breast naughtily shown (11)

'fans the flames' is the definition.
(both can mean to make something worse)

'old lover with super breast naughtily shown' is the wordplay.
'old lover' becomes 'ex' (I've seen this in other clues).
'with' indicates putting letters inside.
'super' becomes 'ace' (synonyms).
'naughtily shown' indicates anagramming the letters (the letters craftily or naughtily move around).
'breast' with letters rearranged gives 'rbates'.
'ace' inserted within 'rbates' is 'acerbates'.
'ex'+'acerbates'='EXACERBATES'

'of' is the link.