EXCLUSIVE

Ladies and gentlemen, prepare for an epic shock -- Anthony Weiner's sexting partner Sydney Leathers has filmed a hardcore masturbation porn ... and TMZ has some pics from the shoot.

Yeah, we saw it coming -- Sydney paid a visit to Vivid porn HQ in L.A. just days ago ... and Vivid's fearless leader, Steve Hirsch, isn't one to waste time.

We've seen the flick, so we'll paint you a picture. Leathers gets naked, strikes a bunch of stereotypical porn poses, and away she goes ... strumming the old banjo.

It's your typical boy-sexts-girl-and-girl-gets-a-porn-deal story. You can check out the full video on Vivid's website. It's your typical boy-sexts-girl-and-girl-gets-a-porn-deal story. You can check out the full video on Vivid's website.

It's unclear how much Sydney got paid.