Chris Pratt and Katherine Schwarzenegger Grab Dinner with His Son, Jack

Chris Pratt and Katherine Schwarzenegger will be starting married life together soon, but they already look like they have the family thing down.

The newly engaged couple hit up the vegetarian restaurant A Votre Sante, Wednesday night in Brentwood, with Chris's 6-year-old son, Jack -- and they all seemed like they were trying to keep it on the DL.

Chris and Katherine wore all-black getups, and he kept his hat pulled down over his face. Kat and Jack went hoodies up, but the kid's red jacket was hard to miss.

Outings together are nothing new for the trio -- they all hit up Disneyland together last month just a few weeks before Chris proposed, and Katherine said yes.

Jack's mom, Anna Faris, is very much down with the engagement news too ... even offering to officiate their wedding. Clearly, they're all about a modern fam.