What took so long?!?

Almost three years after Mel Gibson drove drunk, insulted Jewish people and referred to a cop as "sugar tits," the actor's wife has filed for divorce.

According to TMZ, Robyn Moore filed legal papers to divorce Gibson, her husband of 28 years, last Thursday. She cited "irreconcilable differences" in the document.

The couple were married in 1980, long before Gibson amassed a fortune estimated at $900 million back in 2006. There's no prenuptial agreement, meaning he stands to lose up to half his earnings.

Ouch. That could hurt Mel more than any comparison to former dictator Saddam Hussein.

Robyn is seeking custory of 10-year old son Tom, along with spousal support and attorneys fees.

** UPDATE: A source confirmed to People that Gibson and Moore have actually been separated for three years. This development simply makes it legal.