Chris Brown's girlfriend Karrueche Tran got a shock when she returned to the star's home to find the R&B bad boy had spray-painted her Porsche.

The model had been on a trip to Las Vegas but jetted back to Los Angeles on Thursday (22Aug13) to see her on/off beau.

Tran was left speechless when she was dropped off at his property and discovered colourful monster murals had been sprayed over the white paintwork of her expensive sports car.

Taking to Instagram.com, she uploaded a snap of herself looking glum while sitting on the vehicle's hood, with the message, "This (is) what the f**k I come home to lmao this n**ga man."

The graffiti is in the same style as the daubings on the outside of Brown's home, which the Kiss Kiss hitmaker was made to remove earlier this year (13) following complaints from neighbors.