Associate’s satisfied cry after swapping leads (9)
I believe the answer is:
bedfellow
'associate's' is the definition.
(bedfellow is a kind of associate)
I don't understand how the rest of the clue works.
(Other definitions for bedfellow that I've seen before include "Close associate or partner" , "Mate" , "Partner (in the boudoir?)" , "Person slept with" , "Colleague" .)