Kendall and Kylie Jenner snapped underage drinking in New York

Kendall and Kylie Jenner must have thought the focus was all on 30th birthday girl Khloe Kardashian when they decided to have a cheeky bevvie at her birthday party this weekend.

The photos above of the 16 and 18-year-old reality TV stars enjoying a tipple of vino at the luxury yacht birthday bash have emerged... And erm, the drinking age in the US was 21 last time we checked.

But hey, it could be sparkling grape juice for all we know!

Check out more snaps from Khloe's "dirty 30" yacht party in the gallery below...