Jenn Rivell lied about Jessica Simpson

Jennifer and Bam were holding out for the highest bidder," says a source close to the former couple, who, we hear, are in on their "feud" together ... Star shelled out $8,000 for "exclusive interviews" with Margera and Rivell in the latest issue, on stands today ... A source close to the Jackass alum says that on April 19 -- the night of Simpson's supposed infidelity -- Margera went back with Jessica and 10 other pals to Simpson's parents' house in L.A. after partying .. at The Roxy until 2 a.m. ... "Everyone slept at Jessica's," says the source, "but no one slept with Jessica, except maybe her little dog."