Ubi et dantis et accipientis turpitudo versatur, non posse repeti dicimus; quotiens autem accipientis turpitudo versatur, repeti posse

When there is turpitude in both the giver and the receiver, we say the thing cannot be recovered, but that whenever the turpitude is in the receiver only, it can be recovered. Mason v Waite, 17 Mass 560, 562.