Khloe Kardashian and sister Kim took in a Lakers vs. Mavericks game last night at the Staples Center. Great to see Khloe supporting her hubby Lamar Odom and his new Dallas team!

But on their way out, the sisters faced questions surrounding Khloe's alleged fertility treatments ... and about reports that claim OJ Simpson, her dad's close friend, is her father.

Kim's younger sis has denied using fertility treatments in the hopes of getting pregnant. She says that she and her basketball hubby are using natural methods.