Negotiate; indulgence (5)
I believe the answer is:
treat
I believe this clue is a double definition.
'negotiate' is the first definition.
(I've seen this before)
'indulgence' is the second definition.
(to indulge yourself is to treat yourself)
(Other definitions for treat that I've seen before include "Medicate" , "Give medical care or free meal to" , "Minister - buy one a drink" , "Handle; dainty" , "Tend" .)