Kourtney Kardashian got a little nostalgic about her brother, and she picked a weird way to show it ... posting a pic of him with his hand down his pants.
Maybe Kourt just discovered that site, or more likely ... she's doing what all the sisters have been doing in recent months -- posting old pics of Rob, which they frequently delete.
Of course, Rob's been out of the spotlight ever since Kim's wedding last year. So, they're either encouraging him to resurface, or just giving him a public S/O to say ... we still got you, bro.
Regardless ... sweet Bundy pose!