PDA at the polo match!

In a clip of Monday's Kourtney & Khloe Take Miami, the E! reality star, 31, goes for a horseback ride with a sexy polo player as her clueless beau Scott Disick looks on.

Naturally, Khloe, 26, roots for her older sister to go with the new guy.

"If I was Kourtney, I'd totally trade up," she says.

Later, Kourtney can't help but gush about the experience.

"Yeah, he was holding me and it was kind of like a sexual experience," Kourtney replies with a chuckle.

The full episode of Kourtney & Khloe Take Miami airs Monday at 10 p.m./ET on E!.