from www.tmz.com – TMZ has learned … former Playboy Playmate Karissa Shannon and her BF, “Smallville” actor Sam Jones, have finally agreed to release their sex tape … and all it took was cold, hard cash — that’s what she said.

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.