"I would have loved to have had them there," Brody Jenner tells PEOPLE of his half-sisters Kendall and Kylie Jenner missing his wedding to Kaitlynn Carter

Brody Jenner will be walking down the aisle soon but a few family members will not be attending his Nihi, Sumba Island wedding to fiancée Kaitlynn Carter.

“My two little sisters, we never even heard from them. They never even RSVP’d I don’t think,” Jenner, 34, tells PEOPLE of his half-sisters Kendall and Kylie Jenner.

“We sent them an invite but we just never heard anything back,” the soon-to-be groom says. “Well, they’ll be missed. I would have loved to have had them there.”

Though Brody claims Kendall, 22, and Kylie, 20, have not responded to their wedding invitation, Caitlyn Jenner has.

Brody Jenner; Kendall and Kylie Jenner
| Credit: Brian Gove/FilmMagic; Jamie McCarthy/Getty

A source close to Caitlyn and Brody tells PEOPLE that “Caitlyn has work commitments that have been set up for months and couldn’t be changed in the end.”

Scheduling conflicts aside, “everything is good between them,” the source says. “She will be throwing a big party for them when the newlyweds return to town.”

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Meanwhile, Brody’s brother Brandon, who is the best man, and mother Linda Thompson are at the Indonesian island. “#JennerIsland celebration continues embracing Balinese culture with @brodyjenner & @kaitlynn #love&marriage,” Thompson wrote on Instagram Monday.

The Hills alum proposed to his model girlfriend, 29, 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,” Jenner said at the time.

In February, Brody revealed it’s been “a couple years” since he last spent time with Kylie, who gave birth to her first child, daughter Stormi that same month.

On the other hand, Caitlyn has been supportive of the couple’s relationship, even celebrating her future daughter-in-law in April when she attended the bridal shower at the Santa Anita Park racetrack in Los Angeles.

“Went to my first bridal shower. I had so much fun! PS so much better than Bachelor parties!” Caitlyn shared on Instagram.

“I’m so happy you were there!!! It meant a lot to me!!” Carter commented.

Carter celebrated her bachelorette party in Colombia in late April.