File this story under … totally gross and inappropriate.

Brody Jenner made himself look like a major creeper while promoting his upcoming show, Sex With Brody, when the topic of his younger sister's sex lives came up.

"Do you seriously think they don't know what's up? They could teach me things!" he told Mirror Online of Kendall Jenner, 19, and Kylie Jenner, 17.

kendall kylie jenner

The former Hills star then took his creepiness another step further, by looping in the other Kardashian sisters. "I mean, look at their older sisters [Khloé, Kourtney and Kim Kardashian]. Are you kidding me?"

While he's clearly making a reference to Kim's infamous sex tape, that's not exactly necessary for a former step-brother to bring up. But hey, whatever it takes to get people talking about his new show, right?

The 31-year-old went on to say how proud he is of the teenage Jenner girls, aside from their extensive knowledge in sexual education. "[Kendall] is incredible. It’s pretty amazing to see what she’s accomplished now at such a young age – both of them, Kendall and Kylie," he said. "It’s fun to watch. [I’m a] proud older brother."

(Note to Brody: Never say "it's fun to watch" in the same interview where you're dishing on your sisters' sex lives. One little mix-up can get you in SERIOUS trouble!)