Alysia & Tyler have been married for 11 years and came into the quad with two school-aged children of their own. Since joining the quad, Alysia gave birth to her third child. Meanwhile, Sean & Taya, married for six years, welcomed her first baby after becoming a quad, and now Taya is about to give birth to her second child. With five kids in the picture, things are bound to get complicated, especially since the biological father of the three younger kids remains unknown. The quad has intentionally chosen not to find out who the father is to avoid jealousy and remain committed and equal parents – which they discover is much easier in theory than in practice. 

In addition to the complex parenting dynamics, dating each other's partners is not without its share of emotional challenges. Non-romantic partners Taya and Alysia must navigate their insecurities and the inevitable jealousy that comes along with this unique relationship. At the same time, non-romantic partners Tyler and Sean often clash over their differing parenting approaches. But with the new baby almost here, the quad must get on the same page sooner than later. Things get even more complicated when later in the season Taya drops a bombshell that threatens to dismantle their fragile family dynamic.