Manga Maou Wa Yuusha No Kawaii Yome Party No Bishoujo 4 Nin Kara Uragirareta Yusha Maou To Shiawase Ni Kurashimasu 4 Nin Ga Yuusha Goroshi No Dai Zainin Toshite Sekaijuu Kara Hihan Sareteru Ma Ingaouhou Kanaa Chapter 5 Repack Work

The manga you're referring to is titled (The Demon King is the Brave's Cute Wife). It follows a hero who was betrayed by his female party members and subsequently finds happiness living with the female Demon King.