Farrah Abraham's ass was up for grabs -- again. The "Backdoor Teen Mom" star got a handful from Chumlee Friday at the Palms pool in Vegas. Farrah was there to celebrate her 24th birthday. Her birthday wish was inspiring ... she wanted a hot guy to rub suntan lotion on her body, and the "Pawnstars" star delivered. Chumlee's making a side career in Vegas. He's coming back to the Palms pool July10 to DJ. Farrah, who is familiar with the signature DJ move, will no doubt show.