Photos: Khloé K and her family celebrate James Harden's 26th All white Birthday party on a yacht

Khloé Kardashian dressed really sexy to her man's -James Harden 26th birthday party.

The duo were spotted at the NBA player's celebrity-filled 26th birthday bash on Tuesday night, looking sexy in white-on-white ensembles that matched the party's yacht theme.

Khloé showed off some serious skin and her super-toned legs in a see-through skirt with two thigh-high slits, which she paired over a lacy white leotard that revealed just a hint of booty. However, she swapped out her swanky Christian Louboutin pumps for a pair of more comfortable white tennis shoes as she made her way off the boat at the end of the long night.

Khloé wasn't the only member of the Kardashian clan in attendance. The Houston Rockets player's soiree included a long list of the reality star's family, including: Kim Kardashian, Kanye West, Kylie Jenner, Tyga, Kendall Jenner and Kourtney Kardashian. Even mom Kris Jenner and boyfriend Corey Gamble made an appearance.

Harden looked like he had the time of his life, still carrying a half-empty bottle and a couple gift bags as he followed his girlfriend off the yacht. He wore an oversize white shirt with white jeans and a pair of high-top sneakers.

The boat took off around 11 p.m. from Marina del Rey, Calif., and set off an impressive fireworks show at midnight. It returned at 1 a.m. to drop off the Kardashians and Jenners, with the exception of Khloé who stayed to party with her beau as more attendees hopped onboard to join the festivities.