Whoa there, tiger!
He captioned the pic, "#Almostnude – you asked for it, you got it. Tryna work that body, tryin', tryin'."
In the snapshot, the actor is shown posing in nothing but a towel in a bathroom mirror.
And based on the revealing image, it's pretty clear that Franco's been logging in a few hours in the gym lately.
But it wasn't his physique that stole everyone's attention during his parody of Kanye West's "Bound 2" music video.
"Bound 3" starred alongside a shirtless Seth Rogen, who posed seductively on a motorcycle while straddling the brunette funnyman.
The shot-for-shot remake was so hilarious that it even earned rave reviews from none other than Mr. West himself.
"Kanye says what's up!," Kim Kardashian tweeted Rogen on Tuesday, Nov. 26. "He loves u guys! He laughed so hard at this." (The original video vixen approves as well, tweeting to the guys Monday they "nailed it" with the clip.)
Franco, who can now add Kanye impersonator to his endlessly long résumé, Instagrammed an image of Rogen with his back-and-forth tweets with Kardashian, writing, "#Sethrogen #kimkardashian #kanyewest - I'M SO GLAD THAT KIM and KANYE LIKE THE VIDEO - BOUNd 3!!! "