“People Collide,” by Isle McElroy, is a delightfully gimmicky novel about how gender is a gimmick. It starts off with a tried-and-true fictional premise, the semi-dysfunctional marriage, but then ...

Two married couples who live and raise their families together — and even swap partners — have opened up about life as a “foursome.” Alysia and Tyler Rogers were already parents to two children, now ...