She has to be a little mortified.

Kourtney Kardashian spent some quality time over the weekend with daughter Penelope, as news broke that baby daddy Scott Disick is dating 19-year-old Sofia Richie, and the reality star seems to be doing her best to take the romance in stride.

The Lord and Nicole Richie's little sis initially denied they were a thing earlier this summer, but there's no hiding it now. The odd couple went public with their relationship during NYFW, and now they're parading their love on their home turf.

"Since returning to L.A., Scott and Sofia are inseparable. They are spending every day together. Sofia seems smitten," a source dished to People.

“It’s obvious that she looks up to Scott. She constantly giggles around him. They are very flirty. Scott takes care of her, opens the car door and pays for everything,” the source added.

LD and Sofia's pairing is weird for a couple reasons. For starters, she used to be close with Kendall and Kylie. She also used to do the deed with Justin Bieber, who famously romped with Kourt as well. As if that wasn't enough, she's "pals" with Kourtney's current boy toy Younes Bendjima.

Kourtney must just want Sofia to go the F away! Watch how Scott reacted when we asked him about Sofia before word got out...