Things are apparently getting tetchy between Zynga, creator of FarmVille and Mafia Wars, and Facebook, host site of said games. A bunch of sources informed TechCrunch that the relationship is currently “intense.” In fact, things have reportedly got so bad that sources are predicting Zynga will walk out on Facebook, and take its highly profitable children with it.

The root of this enmity lies in Facebook’s decision to place limitations on Zynga messaging users, and its decision to use “Facebook Credits” as its exclusive payment platform for Zynga’s games; Facebook takes a 30% tax from all Facebook Credits it sells, which is apparently grating somewhat with Zynga.

Where would the likes of FarmVille and Mafia Wars go in the event of a divorce? Well, the company already has plans, if one leaked internal mail is correct. Apparently, Zynga CEO Mark Pincus is planning to launch Zynga Live, a new social gaming network dedicated to the likes of FarmVille and Mafia Wars.

Zynga has declined to comment on any of this, but Facebook did reach out with some typically bland corporate speak:

“We have conversations with our large developers all the time and we don’t typically comment on specific discussions. But generally, our priority is to ensure a quality experience for Facebook users while fostering an innovative and dynamic environment that offers meaningful opportunities for all developers on Facebook Platform.”

[Via TechCrunch]