from www.tmz.com – What do you do when one of your three-way sex tape partners blocks the sale of the flick? If you’re “Bad Girls Club” hell-raiser Erica Langston … you simply sell your OTHER sex tape. Duh.

Sources tell TMZ Langston and one member of the ménage à trois — her boyfriend Adrian — tried to sell their masterpiece to Vivid Entertainment head honcho Steve Hirsch earlier this week … but sex tape partner numero tres threw a wrench in the deal.

We’re told #3 — who happens to be one of Langston’s “BGC” castmates — demanded way too much scratch for the tape … around $200k … so the deal went sour.

But our sources say Langston had an ace in the hole — another sex tape with Adrian … sans her financially demanding XXX cohort.

We’re told Hirsch made a new offer for the two-person porno … and that the deal is all but sealed.