The Cheaters Tour

Works for, by or containing cheaters:

Gabrielle d'Estrées and One of Her Sisters, 1600s: king, his cheatin' wife and his loving mistress.
King Charles & wife holding up their... intestines! (1370s): king, loyal wife and cheatin' ex-wife.
Liberty leading the people, 1831: artist's real daddy was a machiavellian French diplomat, Talleyrand.