Race around dodgy bars with gin in mum's cups (7,3)

'mum's cups' is the definition.
(as in bra cups)

'race around dodgy bars with gin' is the wordplay.
'race' becomes 'run' (synonyms).
'around' is a reversal indicator.
'dodgy' indicates an anagram (a dodgy or wrong order of the letters).
'with' means one lot of letters go next to another.
'run' backwards is 'nur'.
'bars' after 'gin' is 'ginbars'.
'ginbars' with letters rearranged gives 'singbra'.
'nur'+'singbra'='NURSING BRA'

'in' is the link.