To clarify, Igraine is the wife of a Marquess but the Marquess makes her sleep with the King?
Iirc, it's more like the King made her the wife of a Marquess so she is in a better status to be his mistress. And the King promised the Marquess that he can get Igraine after the King is bored with her.
To clarify, Igraine is the wife of a Marquess but the Marquess makes her sleep with the King?