Man whose wife has been unfaithful to him

One word substitute is Cuckold.

Dandy: a man unduly concerned with looking stylish and fashionable.
Bastard: an unpleasant or despicable person.
Concubine: a woman who lives with a man but has lower status than his wife or wives.
Cuckold: a man whose wife is sexually unfaithful, often regarded as an object of derision.