Greg Penner
Gregory B. Penner( born December 18, 1969) is an American businessman and venture capitalist.
Penner was named the chairman of Walmart on June 5, 2015.
He is the son-in- law of S. Robson Walton and the grandson- in- law of Sam Walton, the founder of Walmart.
Robert W. Levering
Robert Woodrow Levering( October 3, 1914 – August 11, 1989) was a U.S. Representative from Ohio, son-in- law of Usher L. Burdick and brother- in- law of Quentin N. Burdick.
Nick Sidi
Nick Sidi( born 22 February 1966 in Manchester, England) is an English actor.
He is the son -in- law of actress Rosalind Knight and brother- in- law of actress Susannah Elliott- Knight.
He often plays drama or comedy roles on television and frequently appears in BBC dramas.
Romanos Argyros (10th century)
Romanos Argyros was a Byzantine aristocrat and son-in- law of Emperor Romanos I Lekapenos.
Robert Vadra
Robert Vadra is an Indian businessman, entrepreneur and the husband of Priyanka Gandhi.
He is the son -in- law of Sonia Gandhi and Rajiv Gandhi, and the brother- in- law of Rahul Gandhi.
Charles Francis Norton
Charles Francis Norton( 1807 – 1835) was a 19th- century Member of Parliament for Guildford.
Norton was also a Captain of 52nd Light Infantry; son-in- law of Sir Colin Campbell; brother- in- law of writer Caroline Norton
Wyndham Goold
Wyndham Goold( 1812-1854) was a Member of Parliament( MP) for County Limerick from 1850 to 1854.
Goold was educated at Westminster School and Trinity College, Dublin.
He was the son in law of Frederick Falkiner Goold, Archdeacon of Raphoe and brother in law of Bishop Hamilton Verschoyle
Errikos Kontarinis
Errikos Kontarinis (Greek: Ερρίκος Κονταρίνης,1906–1971) was a Greek actor and cinematographer.
He was born on the island of Tinos in 1906 and died on 11 September 1971.
He was married to Marika Nezer.
Marika Nezer
Marika Nezer (1906 – 18 July 1989) was a Greek actress.
She was the daughter of Konstantinos Nezer, brother of Christoforos Nezer (1903–1996) and cousin of Christoforos Nezer (1887–1970) and granddaughter of Christoforos Nezer, fort chief of Athens and an aide-de-camp of King Otto of Greece.
Lee Chan-hyuk
Lee Chan- hyuk( born September 12, 1996), is a South Korean singer, songwriter and producer.
He debuted as a member of the sibling duo AKMU in April 2014, under YG Entertainment.

Question: Who is the sibling-in-law of Errikos Kontarinis?
Answer: Christoforos Nezer