A sweet little thing to play with (6)
I believe the answer is:
trifle
This clue is a quadruple definition!!
'a sweet' is the first definition.
(trifle is a kind of sweet)
'little' is the second definition.
(thesaurus)
'thing' is the third definition.
(I have seen 'Insignificant thing ' mean 'trifle' so perhaps 'thing' could also mean 'trifle')
'to play with' is the fourth definition.
(I've seen this before)
(Other definitions for trifle that I've seen before include "Play - trivia" , "Pudding - bagatelle" , "more than half of 13 [AFTERSHAVE], for example" , "Thing of little value or importance" , "A desert of no importance" .)