Cuckquean is just the word for the female equivalent/gender-opposite of cuckold. No more no less. If you consider that there are willing cuckolds and unwilling cuckolds then there are willing cuckqueans and unwilling cuckqueans.
A cuckold/cuckquean is someone who has an adulterous partner.
If a person has a cuckquean/cuckold fetish on the other hand then it's usually implied that they want it to happen, that they're willing (and the adultery then is often fake/consented - which is why you don't typically refer to swingers as cuckolds/cuckqueans). But most of the time the people who are made into cuckolds/cuckqueans by their adulterous partners aren't willing.
