Jessica Simpson Lawsuit -- Papa Joe Sues ... This Guy Is Extorting My Family!

Joe Simpson claims the guy suing him, Jessica and family for $12 million is simply trying to extort the Simpson family over a supposed deal that never came to fruition.

In the lawsuit -- filed in New York -- Papa Joe does say he was working with Jeffrey Bowler in 2010, but says that deal "died on the vine" way back when and has nothing to do with the mega deal that came five years later.

Furthermore, Joe says the deal he was working on with Bowler was to license her makeup line only ... and had nothing to do with selling the entire product line.