Yes, it’s dirty and it’s genuine (4-4)
I believe the answer is:
true-blue
'yes it's dirty and it's genuine' is the definition.
I know that 'genuine' relates to this answer.
'dirty and it's genuine' is the wordplay.
'dirty' becomes 'blue' (blue can mean pornographic).
'and' means one lot of letters go next to another (I've seen this in other clues).
'it's genuine' becomes 'true' (synonyms).
'blue' after 'true' is 'TRUE-BLUE'.
Can you help me to learn more?
(Other definitions for true-blue that I've seen before include "Staunchly loyal Conservative" , "Staunchly loyal (Tory?)" , "staunchly faithful" .)