Where one pays for the other doorbell to be fixed (8)
I believe the answer is:
bordello
'where one pays for the other' is the definition.
('the other' is old-fashioned slang for 'sex')
'doorbell to be fixed' is the wordplay.
'to be fixed' indicates anagramming the letters.
'doorbell' with letters rearranged gives 'BORDELLO'.
(Other definitions for bordello that I've seen before include "Congress here" , "Where one pays for the other" , "House of ill repute" , "12 across (anag)" , "House of ill-repute" .)