(1) He is married to Anna Klazes Hoekstra.
They got married on June 10, 1869 at Tietjerksteradeel, Friesland, Nederland, he was 31 years old.Source 3
(2) He is married to Anna Maria Nicolai.
They got married on November 26, 1876 at Smallingerland (Fr) , he was 38 years old.Source 4
www.wiewaswie.nl
http://www.graftombe.nl/names/info/463332/otten
Huwelijksregister 1869, Tietjerksteradeel
Huwelijksregister 1876, Smallingerland