"It was his first love scene but I've done them over the years and they're funny," J.Lo said. "They're uncomfortable, obviously because you're being intimate with someone who you're not really intimate with, and it's all fake at the end of the day."
The 45-year-old "Booty" singer stars as Clair Peterson, a bored, divorced housewife that gets into a sexual tryst with her teenage neighbor Noah, played by Step Up Revolution and Step Up All In star Ryan Guzman.
After their night of passion, the boy quickly becomes obsessed with her and that's when things get dangerous. Think Mark Wahlberg in Fear.
Ryan Guzman is 27 in real life and grew up knowing J.Lo as an international pop star, but he had a trick for not being intimidated during their steamy scenes.
"If I thought about it I knew I was going to have that guy moment and it was going to be super awkward between us, so I waited until everything was done," said Ryan. "Until I was home by myself."
The Boy Next Door hits theaters on Jan. 23, 2015.