Demi Moore and Ashton Kutcher split up last November, shortly after his penis tripped and fell into another woman. So why haven't either of them filed for divorce yet?

Turns out it's all about the benjamins.

In the year since their separation, Demi smoked something she had no business inhaling and Ashton started swapping spit with Mila Kunis. You'd think they'd both be ready to get this whole marriage thing over with, but then there's that little matter of money.

The former May-December couple is supposedly "trying to negotiate a settlement out of court and out of the public eye," a source says.

They have yet to reach an agreement over the cash, and Kutcher seems to be the sticking point -- he earned substantially more than Moore did during the later stages of their six-year marriage, and he doesn't want to fork over a large settlement to his ex. You'd think a dude who cheated on his wife and was the highest paid actor on TV last year would just write a check to end things peacefully, but no dice.

Sources say that despite the former couple's efforts to keep this dispute private, a messy public court battle could ensue if Kutcher continues to hold out. And upon hearing that, the tabloids are just hoping he will.

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