Kylie Jenner has flown to Mexico with Tyga to continue her birthday celebrations.

Kylie Jenner and Tyga

Kylie Jenner and Tyga

The 18-year-old reality TV star took a private plane on Monday (10.08.15), the day she reached the milestone age, and Us Weekly reports her destination was Mexico with the 25-year-old rapper.

Kylie posted a picture of the jet beside the brand new $320,000 Ferrari which Tyga bought for her on her Instagram page and captioned it "Gone".

Tyga presented Kylie with the car at her birthday party at Bootsy Bellows in West Hollywood on Sunday (09.08.15) night and onlookers said the pair - who have never confirmed they are dating - looked smitten with each other.

One eyewitness said: "He was a very doting boyfriend. He was taking her photos for her, leading her around the bar. The family was really spoiling Kylie. You can tell she felt like a princess."

Meanwhile, Kylie's brother Rob Kardashian skipped her birthday celebrations amid claims he is distancing himself from his family.

A source said of Rob, who longer appears on reality TV show 'Keeping Up With the Kardashians': "Rob refused to do anything for Kylie's birthday. He is invited to everything and he refuses to come to anything.

The insider added to RadarOnline.com: "He's just ignoring everyone. His mom, his sisters. He just doesn't care."