The heartless French mom accused of blindfolding her two young children and abandoning them in a Portuguese forest has been nabbed — casually wolfing down pastries at a cafe without a care in the world.

Marine Rousseau – a self-described sexologist – was nabbed Thursday at a Fátima cafe with her ex-cop beau Marc Ballabriga just two days after the couple allegedly dumped her helpless 3- and 5-year-old children in a remote forest and took off, according to Portuguese and French media.

“They acted as if nothing had happened,” cafe owner Jorge Lopes told MetroUK, describing how the ghoulish couple was calmly basking on the terrace for hours before cops finally arrived. 

“They stayed sitting and didn’t seem nervous. They were searched and handcuffed without any stress at all. When I saw them so at ease in front of the authorities, I was astonished. It was as if they didn’t have blood running through their veins.”

The twisted duo put on a bizarre courtroom spectacle Saturday as the 41-year-old mom sang to herself while Ballabriga, 55, screamed “I love you” in French as he was hauled into the pre-trial detention hearing.

Rousseau kept mum in court, refusing to explain why she allegedly ditched her young sons in the woods after luring them into a fake treasure hunt and blindfolding them thousands of miles from their northeastern France home, SIC Notícias reported.

The couple, who have no connection to Portugal, were slapped with child endangerment and abandonment charges, while Ballabriga – a former French cop who quit the force in 2010 – was also nailed with an aggravated assault charge.

A judge ordered them held behind bars pending trial, with Rousseau — who describes herself on LinkedIn as a sexologist in “body-oriented practices, psychotrauma and developmental dynamics” — sent to the notorious Tires Prison, a major women’s facility west of Lisbon.

Rousseau’s terrified sons were rescued by local baker Artur Quintas after he spotted them “screaming and crying” while frantically stumbling along a main road in Monte Novo do Sul on May 19.

The boys were carrying backpacks stuffed only with clothes, water, and snacks.

He recalled the elder brother telling him their mother and her beau allegedly led them into the forest and covered their eyes as part of a game – but when they removed their blindfolds, she was gone.

The deserted youngsters have since been placed in temporary foster care, as their biological father – who reported them missing on May 11 – moves to bring them back to France. 

The horrified dad, who reportedly divorced Rousseau two years ago and has limited and supervised visitation rights, called the situation “deeply shocking.”

“It’s only a matter of days before I get my children back,” he told French broadcaster Ici Alsace TV on Monday.

“I think about them every second since the Colmar police station contacted me to tell me they were missing. My children will have to rebuild their lives, just as I rebuilt mine, and they don’t need to be constantly reminded of this tragedy,” he continued.

“I’m not trying to defend or minimize what happened – it’s deeply shocking.”