Jack Osbourne: Ex-GF Keyed My Aston Martin

Cops rolled over to Jack Osbourne's Hollywood Hills mansion this week after a woman pulled out a key and slashed the hell out of his super-expensive Aston Martin ... and it was all caught on tape.

Law enforcement sources tell TMZ surveillance cameras on Jack's property rolled when the perp attacked the reality star's $250,000 ride on Wednesday -- causing at least $10k worth of damage.

We're told the woman was identified as an "ex." Cops eventually tracked down the woman and arrested her for felony vandalism.

Calls to Jack's rep were not returned.

SOURCE: TMZ.COM