Bitterness about the rough frisking? (4,8)
I believe the answer is:
hard feelings
'bitterness' is the definition.
(thesaurus)
'rough frisking?' is the wordplay.
'rough' becomes 'hard' (similar in meaning).
'frisking?' becomes 'feelings' (I can't justify this - if you can you should believe this answer much more).
'hard'+'feelings'='HARD FEELINGS'
'about the' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for hard feelings that I've seen is " Resentment".)