Yeah, NBD. Just breakfast with his GF, Katherine Schwarzenegger ... and her dad, Arnold. If it looks like Chris is breathing a deep sigh of relief -- you try sitting across a breakfast table from the ex-Governor slash Conan the Barbarian slash 7-time Mr. Olympia.

Chris and Katherine double dated Sunday morning in Santa Monica with Arnold and his GF, Heather Milligan.

Hard to get a read off Arnold's face about how the sit-down went, but what could go wrong, right? It's Chris freakin' Pratt ... everyone loves him, right?

Right after their meal, Chris and Kat headed to the chapel! Nothing for Ahnald to get antsy about -- they were just attending their usual Sunday services.