Defacto wife became deceitful (3-5)

I believe the answer is:

two-faced

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(Other definitions for two-faced that I've seen before include "Deceitful, double-dealing" , "Deceitful like Janus, Roman god of doors" , "Perfidious" , "Deceitful or insincere - on the double?" , "Deceitful, with double visage" .)

I've seen this clue in the Sydney Morning Herald.

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