Brody Jenner is preparing to tie the knot with his partner. A couple of his family members won't be in attendance for the big day.

Kylie And Kendall Jenner Didn't Bother To Respond

The Hills alum is getting hitched in Nihi, Sumba Island, to fiancée Kaitlynn Carter. However, he noted that at least two members of his famous extended family won't be there to celebrate with them.

"My two little sisters, we never even heard from them. They never even RSVP'd I don't think," revealed the 34-year-old to PEOPLE, referring to half-sisters Kendall and Kylie Jenner.

Brody acknowledged that he and his soon-to-be wife would love to have them to be there, but they haven't received any response.

"We sent them an invite but we just never heard anything back. ... Well, they'll be missed," he said.

Sharing The Happy Moments

Although 22-year-old Kendall and 20-year-old Kylie have ignored their wedding invites, one person who responded is Caitlyn Jenner. A source confirmed that the elder Jenner has work commitments that unfortunately can't be changed.

Things are good between the two of them, at least, with Olympian and trans rights activist Caitlyn, who's planning to throw a big party for her son and his new wife once they return home to California.

Brandon, brother and best man to Brody and their mother Linda Thompson are all already on the Indonesian island, getting ready to celebrate. Thompson took to Instagram Monday to share how much fun they were having embracing the culture on #JennerIsland.

Reality star Brody proposed to his 29-year-old model girlfriend in May 2016 after two years of dating.

"I couldn't be more in love with this woman and I can't wait to spend the rest of my life with her," Brody gushed at the time.

Ongoing Family Drama

Back in February, Brody confirmed he hadn't spent any quality time with Kylie in a couple years. The youngest member of the extended Kardashian-Jenner clan gave birth to her first child, daughter Stormi, on Feb. 1. Brody claimed at the time he hadn't even known she was pregnant.

Caitlyn, meanwhile, has been hugely involved in her son's relationship, she even attended Carter's bridal shower in L.A. last month. She shared a post on Instagram at the time that it was more fun than a bachelor party.

It's unclear why Kendall and Kylie opted not to attend Brody's nuptials. However, there's a reportedly planned Los Angeles-based reception, so they may be looking to celebrate with him there instead.

Kylie was last spotted with baby daddy Travis Scott, sitting courtside at the Houston Rockets game this past Monday. Kendall, on the other hand, spent a quiet Memorial Day with sister Kourtney Kardashian and some friends.