If you think this whole Kourtney Kardashian/Justin Bieber hookup is totally weird — you’re not alone!

In fact you’re allegedly in pretty good company! According to a new report, Kendall Jenner is totally bothered by her older sister, 36, getting down with her good friend and rumored ex, 21!

RELATED: Kourtney Kardashian Responds to Rumors She’s Hooking Up With Justin Bieber

kourtney and justin

Apparently the supermodel, 20, thinks it’s “just creepy” that her sister is rebounding with a much younger dude!

“Kendall thinks the whole thing between Kourtney and Justin is weird. It’s just creepy,” a source tells Hollywood Life. “First off, Justin is Kendall’s good friend. He used to date her best friend Hailey [Baldwin]. Plus, he’s just too young for Kourtney.”

RELATED: Is Kourtney Kardashian Saint West’s Godmother?

Apparently her critiques of the new couple don’t stop there.

The source continues, “He’s a complete player and for the life of her, Kendall doesn’t understand what Kourtney and Justin have in common. They both downplay their flirting with each other when they’re around Kendall, but she’s not an idiot. She knows something’s brewing between them and it’s just bizarre to her.”

Well, it's safe to say she's definitely not the only one feeling that way!