He is married to Willemina Pietersdr Glerum.
Permission for the marriage has been obtained in Kruiningen on June 3, 1757.Source 1
919. Otr. 3 juni, attestatie gegeven 21 juni, Claas Vervennen, jm. van Yerseke en wonende aldaar, met Willemina Pietersdr. Glerum, jd. van Cruiningen.
Kruiningen index ref. trouwen 1671-1810 https://geneaknowhow.net/script/zee/Trouwen%20Kruiningen%201671-1810.pdf