A cuckquean is the gender-opposite of a cuckold, derived from Middle English (1562 CE).
A cuckquean is a woman with an adulterous husband. In modern English it generally refers to a woman whose fetish is watching, and deriving sexual pleasure from watching, a man having sex with one or several women besides his girlfriend, fiancée, wife or other long-term female sex partner.
Cuckqueanry as a fetish
A cuckquean fetishist is aware of her spouse's activity, sometimes actively encouraging it, and derives sexual pleasure from it. Among fetishists, the cuckold's humiliation or victimization is a major element of the paraphilia.
In the fetish cuckqueaning subculture, the male takes on the role of being sexually dominant, while the female takes on a submissive role. The wife usually only becomes involved with the man or his lover when he permits it—sometimes remaining altogether celibate.
When the fetish is simply heterosexual, the wife has sex only with her husband; when it is bi-sexual, the wife has sex with both her husband and the other woman, or only with the other woman.
The fetish specifics can range wildly. Sometimes the husband and his lovers can treat the cuckquean lovingly; sometimes it involves nothing but swinging, swapping husbands or sharing a lover. But when it goes beyond this, the fetish can require that the cuckquean be humiliated or debased. Sometimes this may be accidental or incidental (e.g., the parties involved are too aroused to stop); but at other times the humiliation may be intentional, and the husband and his lovers act out a story or perform a ritual in which they force the cuckquean to perform humiliating acts, or enter into circumstances that debase her.