Kourtney left baby Mason home in the capable hands of Kris, Kim and Khloé and jetted off with Scott to Sin City, where she hosted a fashion show for Dash at Jet nightclub in the Mirage.
The last time they were there, Scott got into a drunken brawl with Rob Kardashian and shoved a $100 bill in a waiter's mouth during Kim's birthday dinner.
So how did he behave this trip?
Luckily, there wasn't a repeat of his a-hole antics this time around. "They were together all night," a source tells E! News of the twosome. "They were holding hands and so cute."
And while new mama Kourt sipped champagne conservatively, Scott was knocking back the drinks.
But at least he kept his bad attitude in check, right? We'll take what we can get.
See what other stars were in Sin City in our Party Pics: Vegas gallery!