'Love & Hip Hop' Star Mimi Faust -- Hardcore Sex Tape ... With Reality Co-Star

"Love & Hip Hop" star Mimi Faust is finally making love not war -- in a BRAND NEW SEX TAPE -- and her partner in slime is her co-star and BF from the reality show.

Vivid honcho Steve Hirsch tells TMZ ... he got hold of the sex tape starring Mimi and Nikko Smith, and then contacted them to sign off on it going public. He says "Love & Hip Hop" producers also gave their blessing ... presumably in an effort to spice up the reality show for next season.

We've seen clips of "Mimi & Nikko: Scandal in Atlanta" ... it's the real deal and it's intense. It's scheduled for release later this month.