Mun Sen subsequently married Yao Chew Mooi (daughter of Yao Swee Lum of Ipoh, a descendant of Kapitan China, Yap Ah Loy), through engaging the services of a matchmaker. As a tribute, he painted a portrait of Yap Ah Loy after their marriage. Together they would have four sons and two daughters. The war years were unproductive as he turned to farming for survival.

1972. Pameran Peringatan Yong Mun Sen/ Yong Mun Sen Memorial Exhibition. Exhibition catalogue 17 March - 4 April. Kuala Lumpur: Balai Seni Lukis Negara/National Art Gallery; Joseph McNally, 1994. 'Yong Mun Sen' Pioneers of Malaysian Art, 70-76.