WARNING: The following contains spoilers for "Synergy," the Season 3 finale of NBC's Good Girls.

One of Good Girls' biggest story beats is the topsy-turvy relationship between Beth (Christina Hendricks) and Dean (Matthew Lillard). His repeated infidelity and bad financial management plunged them into debt, forcing Beth to recruit her girlfriends for a life of crime they can't come out of now.

Season 3 saw the couple make amends, though, with Dean forgiving Beth for sleeping with Rio (Manny Montano) and also, the villain shooting him. He also changed his ways, opting against transgressions with other women. However, as Season 3 wraps, Beth and Rio's new business venture could be Dean's breaking point, damaging the marriage forever.

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Beth wants to wash money in a business of her own, seeking to buy the spa business from Dean's ex-boss, Gayle. It's a very testy pitch, though, because Dean resigned after he and Gayle kissed and almost slept together. He told Beth he didn't but part of her doesn't trust Dean. Still, she proceeds with the offer because she sees this as her way out. She could leave the counterfeiting aspect of her partnership to Rio and use the spa sales to wash her own money and even earn genuine revenue.

However, Dean is shocked as he doesn't know where they'll get the money for such a high offer to Gayle, but he quickly pieces together the backer's Rio. He doesn't want him involved but Beth keeps lying to him. Dean remains suspicious as he knows the authorities won't ever suspect this business for laundering. When Beth returns to Gayle alone, however, it takes a dark turn as Gayle reveals she and Dean did sleep together and Beth's falling for his lies again. No one knows the truth but Beth pulls the plug, leaving in a fit. This inspires her to use Rio's goons to then rob the place, leaving it an empty husk.

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It's a win-win because when she goes with a third offer for Gayle, it's much lower. Gayle's forced to accept it, realizing she underestimated Beth. The finale ends with Beth and Rio walking through the place, planning for the future. However, Beth's empire isn't what she imagined because Rio's forcing her to still print fake money for him and wash all his cash here. She's pissed but still, the cut will be massive so it's just her job not to get caught.

As for Dean, he tried to proclaim innocence when Beth confronted him about if he would have slept with Gayle in his bad phase, and from his honest remarks about Gayle's body, Beth thinks he really did cheat again. So at this point, she seems to have written Dean off, but this time it doesn't seem like he'll come begging. After seeing her dollying herself up for their meetings all season long, Dean believes she's still sleeping with him.

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To him, that's why Rio cleaned out their house because he's emotional over Beth and Dean. Little does Dean know she dolled up so he wouldn't kill her, but once more, mistrust and insecurity reign supreme in the Bolland home. This creates major potential problems because if Dean does indeed turn on Beth, he has evidence of the operations that could damn her and Rio. He may even prefer a less aggressive method, which is to partner with Gayle and try to put them out of business. Either way, the battle lines are drawn as Beth seems to have lost faith in Dean.

Good Girls stars Christina Hendricks, Mae Whitman, Retta, Matthew Lillard, Reno Wilson and Manny Montana.

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