“Let’s Stay Together” is the story of Stacy Lawrence, a pediatrician who is engaged to Charles Whitmore, the contractor she hired to remodel her kitchen. Stacy and Charles have a fun, sexy, intense dynamic. However, six months in, some of the magic of finally finding a soul mate has worn off, and they find themselves constantly renegotiating their rules of cohabitation.
In contrast, Stacy’s super-fabulous younger sister Tasha and her husband Jamal act like an old married couple even though they’re only in their 20s. Tasha made a lot of mistakes in love before she found a stable, ambitious guy like Jamal so she has dedicated herself to pleasing her man and raising their six-month-old twins. Jamal considers himself lucky to have a fine, dedicated wife like Tasha even though she does bring the drama on a regular basis.
Charles’ earthy younger sister Kita, a proud employee of the DMV, is celebrating her independence by taking a break from dating while she explores all that life has to offer before she settles down.
Stacy and Charles spice things up in the bedroom but soon find themselves exhausted. Elsewhere, Jamal objects to Tasha's wardrobe choice for their son during a photo shoot.
Charles meets Stacey's med school friends; Jamal's client's attempt to seduce him.
Charles and Stacy go to pre-marital counseling; Kita makes Tasha jealous.
Stacy hires Charles to renovate her office; Kita has romantic dreams of Jamal.
A gift from Stacy's old boyfriend bothers Charles, so he decides to replace it; Tasha worries she's less attractive now that she's a stay-at-home mom.
Charles hires a wedding planner since Stacy is procrastinating; Tasha becomes an entrepreneur.
Stacy is offended and gets in a fight with Tasha; Jamal and Charles sneak around to see each other.
Stacy exhibits cold feet at her engagement party, prompting Charles to question if she's ready to get married. Elsewhere, Jamal discovers that Tasha's father is still supporting her financially.
Charles and Stacy reconnect, but Charles thinks they should keep their distance until Stacy sets a wedding date. Elsewhere, Jamal and Tasha attempt to write a children's book.
Stacy goes on a date to test her feelings for Charles; Tasha tries to impress a mothers' group; and Charles reflects on his problems after a visit with his dad.
Tasha and Jamal arrange a reunion for Stacy and Charles, but the plan hits a snag when their intended targets each bring dates.