He's the king of the selfies!

And now even David Letterman wants to know about James Franco's fascination with selfies! When the Palo Alto actor appeared on last night's Late Show with David Letterman, the hilarious host took the opportunity to confront the actor about his penchant for posting racy selifes and the constant controversy surrounding his Instagram account.

"To me it's just a fun thing. It's something I don't put a ton of thought into but it gets a lot of attention. It gets a lot of attention. I have a ton of followers on Instagram."

In the sit down, the 36-year-old even likened his recent hand-down-the-tighty-whities shot to the Britney Spears' infamous head-shaving meltdown.

Franco explained, "Like that Britney Spears shaved head moment, where it's sort of like, 'All right, you want me? Here you can have me, but I am going to be really ugly.' You know what I mean?"

And while he has gotten a lot of flack for some of his pics, the sexy actor cautioned Dave and any other critics, by saying, "If you don't want to see it don't follow me on Instagram!"

Check out some of Franco's many selfie moments -- and keep in mind: these are only from the past three weeks!