The REAL reason behind this Hollywood couples split...

ANNA FARIS and CHRIS PRATT haven't come out and said exactly what led to their split, but that hasn't stopped those pesky ANONYMOUS SOURCES from chiming in.  Here's the latest:

 

 

Anna wanted a traditional family, while Chris is having too much fun being a movie star.  Remember, SHE was the bigger star when they got married back in 2009. 

 

 

So at the time, he was probably fine with the idea of having a home base in L.A., staying close to it, and making lots of babies.  And they do have ONE kid, a son named Jack.

 

 

But then Chris became one of the biggest actors in the world, and everything changed.  He's doing movie after movie, which keeps him away from home for months at a time.  And he doesn't want any more kids for now.

 

 

Anna's main job right now is a steady gig on the CBS comedy "Mom".  But she did just shoot the remake of "Overboard" . . . which is coming out next spring. 

 

 

(TMZ)