This storyline is controversial because it undermines the "happily ever after" with Oz. Jill begins secretly meeting Marco to help him find a job, but the meetings become emotional infidelity. She is drawn to Marco because he represents her origin—the ghost of who she could have been if she hadn't become a cop.

Their relationship begins as a cat-and-mouse game during a counterfeiting investigation. Liam provides Jill with a key piece of evidence, but only after a flirtatious encounter in a jazz bar where he quotes Nietzsche. Critics often call this the "Grey Zone Arc" because the romance blurs every ethical line.

However, the "Oz Relationship" is defined not by passion but by compatibility . They are a seamless unit. The conflict arises externally: when Oz is promoted to Lieutenant, he becomes Jill’s superior officer. The fraternization policy forces them to choose. Jill, fearing her career defines her, nearly breaks it off. Oz’s response is the most romantic line in the series: "Then I'll quit. There are a thousand precincts. There's only one you."

In her early twenties, before the badge, Jill was engaged to a fellow academy recruit named . Their storyline is a tragic prequel shown in fragmented flashbacks. Marco was earnest, idealistic, and believed love could conquer the ugliness of their future profession. The relationship imploded not because of infidelity, but because of protection . When Marco discovered Jill’s father was trying to contact her from prison, he pushed for reconciliation. Jill, terrified of her past contaminating her future, sabotaged the relationship by picking a vicious fight, accusing Marco of being "too soft." This storyline establishes the Mendoza Paradox: She craves love but destroys it preemptively to avoid being destroyed by it. Season 2-3: The Forbidden Tango with "Fixer" Liam Vance Jill Rose Mendoza’s most iconic and controversial romantic storyline is her slow-burn, morally gray relationship with Liam Vance , a charming but ruthless "fixer" for a shadowy private intelligence firm. He is not a villain, but he operates in the gray area where Jill’s conscience lives.

They end the season in an ambiguous domesticity—his toothbrush at her place, her case files on his table. It is the first mature, sustainable relationship in Jill’s arc. No long-running romantic storyline is complete without the regression arc. In the latest season, a newly paroled Marco Diaz (her first fiancé) re-enters the picture. Marco is no longer the earnest rookie; prison has hardened him into a cynical mirror of Jill.

Fans speculate about upcoming storylines: Will Liam Vance return for one last heist? Will a new villain use Oz as leverage against her? Or will Jill Rose finally get the one thing she has never had—a stable, boring, beautiful love?

The storyline with Sam focuses on physical intimacy as a metaphor for healing. In one pivotal scene, Jill has a nightmare about a case and wakes up swinging. Sam doesn't flinch. He simply holds her wrists, not to restrain her, but to anchor her. "You don't have to be on watch with me," he says.