A little fruit ... dirty fruit (9)
I believe the answer is:
blueberry
'a little fruit' is the definition.
'blueberry' can be an answer for 'fruit' (blueberry is a kind of fruit). I am unsure of the 'a little' bit.
'dirty fruit' is the wordplay.
'dirty' becomes 'blue' (blue can mean pornographic).
'fruit' becomes 'berry' (berry is a kind of fruit).
'blue'+'berry'='BLUEBERRY'
Can you help me to learn more?
(Other definitions for blueberry that I've seen before include "North American fruit (with which to make pies)" , "fruit plant" , "North American soft fruit" , "Small succulent fruit" .)