He blames the Big C — both of them.

A nutty drug addict who swiped jewelry and a $100,000 watch from the Plaza hotel suite of a princess blamed his sticky-fingered spree on several relatives being ill with cancer.

The nonstop run of bad news, he insisted yesterday, got him hooked on cocaine.

“It was only a matter of time before I started to commit crimes to support my drug habit,” James Bennett babbled just before being sentenced to 10 years in state prison.

In a rambling speech in Manhattan Supreme Court, Bennett, 45, apologized to Princess Arwa Al Qassimi of the United Arab Emirates for stealing from her $230,000 in cash, handbags, jewelry and a watch with diamonds spelling “Allah” on its face.

The ex-con said he had resumed drinking and using cocaine after cancer killed his grandmother and sister-in-law and his parents wrestled with illness.

Justice Edward McLaughlin, after letting out a sigh, said Bennett has only himself to blame for his drug addiction.