It's Throwback Thursday!
The expectant mother captioned the pic on Instagram with, "#throwbackthursday me & @kourtneykardash fun in the sun! #bikinibabe"
Little Kim looked positively precious in a silver two-piece while holding hands with her older sister.
Kourtney made a funny face while posing in her blue-and-white striped one-piece swimsuit.
What a flashback!
A new season of Keeping Up With the Kardashians premieres June 2 at 9 p.m., only on E!