Liberal ideas shocked mum's new Lothario (6,3)
I believe the answer is:
ladies man
'lothario' is the definition.
(I've seen this before)
'liberal ideas shocked mum's new' is the wordplay.
'liberal' becomes 'l' (abbreviation).
'shocked' indicates an anagram (letters are shocked or disrupted).
'mum' becomes 'ma' (both can mean mother).
'new' becomes 'n' (abbreviation as in New Testament NT).
'ideas' is an anagram of 'adies'.
'l'+'adies'+'ma'+'n'='LADIES' MAN'
(Other definitions for ladies man that I've seen before include "Rake" , "Libertine" , "Womaniser" , "Say, Don Giovanni" , "Philanderer" .)