Chris Pratt, Katherine Schwarzenegger Just Horsin' Around ... For Thanksgiving

11/23/2018 7:49 AM PST

Chris Pratt and Katherine Schwarzenegger Horse Around During Thanksgiving

EXCLUSIVE

Chris Pratt and Katherine Schwarzenegger got all Kennedy fam for Thanksgiving ... goofing around and playing a little football.

Katherine and mom Maria Shriver spent Thanksgiving morning on a hike and then watched as the guys got into it with the pigskin.

It's actually a momentous and sad day in the Kennedy family ... 55 years ago yesterday, Maria's uncle, President John F. Kennedy,  was assassinated in Dallas. Football is a significant sport because JFK and the brood always played during holidays.

It's clear, Chris and Katherine are super serious ... almost a year after his split from Anna Faris.

Arnold Schwarzenegger was nowhere in sight ... we're told the kids had dinner at Maria's, and Arnold hosted some gym buddies and other friends at his home. Still, the fam is still super tight.