Kim Kardashian wore a blue corset dress to Khloe's 30th birthday party on June 27. Credit: Splash News

It may have been Khloe Kardashian's 30th birthday celebration, but, as per usual, all eyes were on Kim Kardashian. The reality star, 33, wore a royal blue Ulyana Sergeenko corset dress with a thigh-high slit and her favorite Tom Ford gold chain heels. 

The plunging neckline showed off Kanye West's wife's ample assets. Her now-pregnant older sister Kourtney went for another bold look in a black and white tbagslosangeles Freesia printed jumpsuit. Her barely-there baby bump was covered up in the loose look. 

The famous family enjoyed a yacht party off the New York harbor in honor of Khloe's milestone birthday. 

Naturally, they took to social media to post pictures together from the family night. The Kardashian-Jenners Instagrammed shots of the Empire State Building and the Statue of Liberty lit up at night. 

The only family member absent was Khloe's brother Rob Kardashian, who has been keeping a low profile since skipping out on Kim's European wedding weekend in late May. Instead he posted several photos with his sister on Twitter wishing her a happy birthday. 

"Happy birthday @khloekardashian," he wrote. "Woot woo LOVE YOU."