How else does one cap off an epically casual birthday? Rob Kardashian gave himself the best gift of all on Thursday, March 17, by cheating on his diet with a late-night In-N-Out burger with girlfriend Blac Chyna.

The social media-happy pair ended their night with some fast food from a drive-thru at the popular west coast chain in Tarzana, California, to cap off a low-key, fun-filled day.

Earlier in the day, the couple rang in Kardashian’s 29th with breakfast in bed, a trip to a few stores, and a little pampering at a nail salon, where they sipped on mimosas.

Later on at night, the pair had a low-key get-together with a few close pals, who sang him happy birthday over a candle-topped birthday cake. (A video from the celebrations didn’t show whether any of his famous siblings were present, though they all wished him a happy birthday earlier via social media earlier in the day.)

Just last week, Kardashian showed off an impressively trimmer figure in a Snapchat video that Chyna, 27, shared as they shopped for new clothes.

“Creep life,” the model captioned the short video clip, in which her love shows off a light gray sweatshirt and matching sweatpants in the mirror of a dressing room.

The pair have been working out together and keeping to a strict diet to help Kardashian slim down.

Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!