Sweaty "PLL" Stud Keegan Allen Strips to His Briefs Alongside James Franco for Gay Porn Flick

James Franco took to Instagram to share a shirtless snapshot with Keegan Allen on the set of their upcoming gay porn drama "King Cobra," which the "Spring Breakers" star is directing.

While James is no stranger to showing off his bod on social media, we can't stop staring at Allen's six-pack abs ... and what he's packing below them.

Both actors flaunt their goods in the pic, sporting nothing but briefs and, in Franco's case, sweat pants.

"King Cobra" will chronicle the murder of gay porn director Bryan Kocis, who was found dead on January 24, 2007, after police were called to a fire at his Pennsylvania home. According to the coroner, Kocis was stabbed 28 times and his throat was cut before the house was set on fire.

Two male escorts, Harlow Cuadra and Joseph Kerekes, were later found guilty for the murder. Prosecutors said their the motive was to destroy competition in the adult industry with the aim of making a lucrative film starring Brent Corrigan – played by Disney star Garrett Clayton -- who testified for the prosecution during the case.

Christian Slater and Molly Ringwald will also play siblings in the film. Check out the "Sixteen Candles" star's first photo from set with her on-screen brother above!