From Fleshbot's review:
Operatives of the Priory of Semen, including penile profiler Dr. Nadia Saint (Missy Monroe) discover that Leonardo Da Vinci painted the Mona Lisa using his own sperm. Determined to resurrect Da Vinci and overjoyed that the master's sperm was not all "lost up a man's ass", they steal the painting and kill anyone who gets in their way.
This is already so much more believable than that whole Virgin Mary thing.
The actors often fall just slightly short of Nelson X's script, which is the most dialogue-intensive porn script since "Personal Best." Somehow this makes the tongue-in-cheek movie better.
Standout sex scenes are delivered by fleshpots Monroe, Hailey Paige, and Tory Lane, and Frank Bukkwyd and Evan Stone ham it up with gusto:Monroe: So Da Vinci jerked off in his paintings?
Stone (as Professor Lee Teabag): It's just the way things were done!
I'm still trying to figure out just what the reviewer meant when he said it was a "tongue-in-cheek movie." I'll keep you posted. In the meantime, just so you know where my mind is, I think that the Priory of Semen is borderline genius, and Lee Teabag isn't far behind. (In the "real" book and movie the character's name is Leigh Teabing, in case - like me - you forgot.) Plus, is there a better possible response to the question, "So Da Vinci jerked off in his paintings?" then "It's just the way things were done!"? I don't think so.
This may be the mythical porno film that has guys actually fast forwarding through the sex to get to the plot. (I mean, probably not, but still.)