Jennifer Lopez with her “The Boy Next Door” co-star Ryan GuzmanGetty Images

Jennifer Lopez turned heads when she arrived at the Golden Globes with her 27-year-old “The Boy Next Door” co-star, Ryan Guzman. But spies said they also left an afterparty together after getting a little closer on a couch.

Lopez, 45, walked the red carpet with Guzman and posed in an eye-popping dress before she presented an award at the Beverly Hilton with Jeremy Renner. But she then also partied with handsome Guzman once the awards were over.

Spies saw the pair at the Weinstein Co. and Netflix’s celebration amid a stream of stars that included Taylor Swift, Benedict Cumberbatch, Katie Holmes, Keira Knightley, Amy Adams, Dominic West, Elon Musk, Rita Ora, 50 Cent and Rosamund Pike.

As they sat on a couch together at the dark, clubby bash, a spy said, “At one point, Ryan moved back on the couch and then he put his arm around Jennifer.” And “they also left together.” J.Lo’s longtime manager, Benny Medina, was also with the pair.

J.Lo has recently denied rumors she’s back on with her former boy toy, Casper Smart, reportedly saying, “I’m single right now, [it’s] really great for me.”

Taylor Swift (from left), Lorde and Selena Gomez attend HBO’s Official Golden Globe Awards Afterparty.FilmMagic

Conveniently, in “The Boy Next Door,” Lopez stars as a divorcee who falls for a younger man, played by Guzman, but learns he has a dark past.

Swift sat with Lorde and pals near movie mogul Harvey Weinstein. When a DJ played a Swift song, Taylor and her pals jumped up to dance. She was also seen with an entourage leaving Warner Bros. and InStyle’s bash, shrieking when another of her ubiquitous tunes at the Globes afterparties was played. (Movie bigs marveled as Swift seemed to get more attention at the bashes than any Hollywood stars.) And married couple Channing and Jenna Dewan-Tatum drew a crowd of admirers when they hit the dance floor to Jay Z and Beyoncé tunes.

At the Weinstein party, guests swilled endless supplies of Moët & Chandon to wash down late-night Fatburgers and fries that were passed around.