Sofia Vergara looked happier than ever while walking the red carpet at the premiere of her new movie, 'Hot Pursuit,' on Thursday. But behind closed doors, the star was sadly dealing with her ex-fiancé's latest attempt to reportedly "emotionally extort" her through the former couple's embryonic custody battle.

“[Thursday was] the most important day of Sofia’s career. She is opening her first movie [as a leading actress], co-starring an Oscar-winner [Reese Witherspoon] — a movie that she executive produced — and Nick is trying to ruin it," a source revealed in a new report.

sofia vergara and joe manganiello

Sofia and Joe at the 'Hot Pursuit' premiere on April 30, 2015.

Earlier this month, Nick, 39, filed a lawsuit against the 'Modern Family' actress, 42, over frozen embryos the couple previously created through in vitro fertilization. In an op-ed for the 'New York Times' published on Wednesday (one day before her premiere), the businessman argued he should have the right to prevent Sofia from destroying their cryopreserved eggs.

Related: Nick Loeb on Embryo Lawsuit Against Sofia Vergara — "I Have Always Dreamed of Being a Father"

“A woman is entitled to bring a pregnancy to term even if the man objects. Shouldn’t a man who is willing to take on all parental responsibilities be similarly entitled to bring his embryos to term even if the woman objects?" he wrote.

sofia vergara and nick loeb

Nick with Sofia in January 2014.

Nick then explained he and Sofia — who dated for nearly four years from 2010 until 2014 — previously agreed to use in vitro fertilization and a surrogate to have a child together. Since their breakup, the actress has allegedly refused "to agree to [the preservation of the eggs] under all circumstances," he said.

While Nick insists the issue is “a parent’s right to protect the life of his or her unborn child,” an insider conversely stated the lawsuit is a result of "his anger over the end of their relationship and [Sofia's] subsequent engagement to Joe Manganiello. He is using his anger to emotionally extort her.”

sofia vergara and reese witherspoon

Sofia with her 'Hot Pursuit' costar Reese Witherspoon at the film's premiere. Photo Credit: Getty Images)

“Sofia does not want to destroy the embryos, she wishes them to remain stored at the clinic. She is focused on her film, moving into her new home, and the most important day of her life — her wedding," the source told 'Page Six.'