My Mom Jayne,' which marks Mariska Hargitay's feature film directorial debut, premiered at the Cannes Film Festival. In the documentary, the actress reveals a shocking family secret she's kept for more than 30 years.

"It was like the floor fell out from underneath me." Mariska Hargitay's new documentary exposes one of her family's biggest secrets. The daughter of blonde bombshell Jayne Mansfield makes her feature directorial debut with the HBO film,