While the Keeping Up With the Kardashians star and the 29-year-old rapper, have not spoken openly about a relationship, the two have been spotted appearing cozy together for months. He had also attended her pre-birthday party at a nightclub in the Bronx on Thursday and gave her three pieces of jewelry, including a diamond ring, and a Jeep (that matches her birthday gown).
Celebrity photos showed the reality star and Montana appearing to kiss and hug at her 30th birthday bash, which took place on a yacht in New York City on Friday, June 27. Her family and fellow stars of E!'s Keeping Up With the Kardashians posted on their Instagram pages several photos from the luxury boat, which sister Kendall Jenner, 18, joked could fit 10 Chevy Tahoes.
Her long-sleeve, draped, cutout crisscross gown was created by Project Runway season 8 alum Michael Costello, who had designed glamorous attire for several of sister Kim Kardashian's BFFs, including Brittney Gastineau and Blac Chyna, to wear at her and Kanye West's wedding. His designs have also been worn by the likes of Beyoncé, who wore one of his gowns to the 2014 Grammys this past January.
At Friday's bash, Kim turned heads herself in a strapless, lacquered blue, draped, corset-style Ulyana Sergeenko Spring 2014 gown.
The guests enjoyed champagne, as seen in a photo shared by "momager" Kris Jenner.
"Thirsty???" she said. "#BoatLife #happybirthdaykhloe."
On Saturday, June 28, many of the family members, including Kris, Kendall (who wore a white crop top and black pants at the party) and 16-year-old sister Kylie Jenner (who sported a camo jacket) took a short helicopter ride to the Hamptons, where Khloe and pregnant sister Kourtney Kardashian (who sported a black and white printed jumpsuit) and her family are filming the spinoff series Kourtney & Khloe Take the Hamptons.
This was the second celebratory weekend in a row for the Kardashian family, who threw Kim and West's baby daughter North West a giant, festival-themed "Kidchella" party on June 21 to mark her first birthday. The child was not spotted at Khloé's parties.