Lusty husband later becoming gross (6)

I believe the answer is:

earthy

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'lusty' is the definition.
(both can mean sexually vulgar)

I cannot understand how the rest of the clue works.

(Other definitions for earthy that I've seen before include "Hearty (anag)" , "Suggestive of soil" , "Natural" , "Dirty" , "Consisting of soil" .)

I've seen this clue in The Guardian.

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