Learn English – Phrase for daily life

Cuckquean is the word you need, a female cuckold (cuckold being the more common word for wittol).

Cuckquean refers to a woman with an adulterous husband. In modern English it generally refers to the sexual fetish in which sexual gratification is gained from maintenance or observation of sexual relations by a man with a woman or a number of women besides his girlfriend, wife or long-term female sex partner, and therefore, the reversed gender roles of a cuckold relationship.

Sadly there is a Wikipedia page so probably counts as sort of general reference.

But to make it a little less general reference I could add some other stuff...

While cuckold and cuckquean are not directly related to the word cuck (passing excrement, shit) as such, the term cucking-stool (corrupted to ducking-stool) has also been called the coqueene-stool and the cockqueane-stool.

OED says of the cucking-stool:

An instrument of punishment formerly in use for scolds, disorderly women, fraudulent tradespeople, etc., consisting of a chair (sometimes in the form of a close-stool), in which the offender was fastened and exposed to the jeers of the bystanders, or conveyed to a pond or river and ducked.

Seems to me that a cucking-stool is more than a dip in the river. If I can find anything ruder or more vulgar I'll add it in.

_{Wikipedia contributors, "Cuckquean," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Cuckquean&oldid=641764807 (accessed February 9, 2015).}

Within the boundaries of the OP, I would suggest the word enthusiasm:

noun

[MASS NOUN]
1 Intense and eager enjoyment, interest, or approval:

ODO

He has lost his enthusiasm in the face of adversity.