Bill, Harry, Paul follow me in admitting guilt (3,5)
I believe the answer is:
mea culpa
'admitting guilt' is the definition.
I know nothing about this answer so I can't tell whether this works.
'bill harry paul follow me' is the wordplay.
'bill' becomes 'ac' (short for account).
'harry' indicates an anagram (harry can mean to attack or spoil).
'follow' means one lot of letters go next to another.
'paul' anagrammed gives 'ulpa'.
'ac'+'ulpa'='aculpa'
'aculpa' put after 'me' is 'MEA CULPA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for mea culpa that I've seen before include "Sorry!" , "Admission of fault" , "Acknowledgment of error or guilt" , "Old Roman admission of guilt" , "Acknowledgement of one's guilt (Latin)" .)