Nothing says happy birthday like a good sister-to-sister belfie! Kylie Jenner wished Kim Kardashian a HBD with this sexy snap of the two at mom Kris Jenner's La Quinta vacation mansion. The family gathered for a pink-themed blowout for KK's 39th and of course, it was epic!

The "low-key" party featured pool time and a lovely dinner with pink balloons and custom-printed napkins because ... why not?! Mom Kris posted this tribute to her favorite child, full of adorable throwbacks. So happy birthday, Kim!