Charles de Bourbon, III duc de Bourbon is your first cousin 20 times removed's partner's great niece's husband.
Shortest blood relationship
Charles de Bourbon, III duc de Bourbon is your 8th cousin 15 times removed.
You → Robert Cecil Whiting (your father)→ show 29 relatives → Gilbert de Bourbon, comte de Montpensier (her son) → Charles de Bourbon, III duc de Bourbon (his son)
