Sources close to the couple tell us they both agreed to a deal with Vivid Entertainment when the offer hit the "six-figure range."
Steven Hirsch -- the president of Vivid -- tells us, "We are excited to finally distribute this amazing DVD. Not only is it extremely kinky for a celeb sex tape, Karissa is absolutely beautiful. And as for Sam, let's just say he's no 'Smallville.' This is sure to be one of our all-time best sellers."
Watch your backs, Paris and Kim K -- sounds like you've got a challenger for the title.