Yellowstone's spinoff Marshals killed off Kayce's wife Monica - but what does that mean for his dating life? "We will see him navigate single dad life while a girl may show interest in him and he's like, 'Wait,'" Marshals star Ash Santos teased exclusively to Us Weekly. "That was probably the most intriguing part for me because we get this new side of Kayce that we didn't get to see in Yellowstone.