The oldest Kardashian sister has been single since splitting from her longtime on-and-off-boyfriend, Scott Disick, in July 2015.
Kourtney, 37, did have a problem with Kylie's sneaky move, but it wasn't for the reason you're probably expecting. "These are the photos you pick?" the mom-of-three asked as she flipped through the profile, which even included that she graduated with a Bachelor's Degree in Theatre Arts and a minor in Spanish from the University of Arizona.
The 18-year-old reality star assured Kourtney that dating apps are a totally "normal" thing to be on these days. "Like, everybody's doing it. I think it's cute," Kylie explained in another snap. "But girls make the first move, so you can make the first move."
At least the Kylie Lip Kit creator had a very good reason for signing Kourtney up for a dating site without telling her -- she just had to "take care of her big sister." OK, that's sweet!