Seth Rogen Returns to Work at Sony ... With Hard Feelings

Seth Rogen is back in the saddle, showing up at Sony Thursday morning, but we're told he feels betrayed by the studio's decision to shelve "The Interview."

If you believe Rob Lowe ... Seth was fuming over Sony's decision Wednesday. Rob -- who was also in the movie -- said he and Seth were in lockstep and that Sony showed cowardice by crumbling.

Sources connected to Seth tell TMZ ... Rob did indeed chitchat with Seth at JFK about the Sony decision, and it wasn't hard to read between the lines that Seth is pissed.

It makes sense ... during the premiere in Hollywood last week ... Seth praised Sony Pictures chief Amy Pascal for having the balls to stand up to the hackers.

The Sony lot probably seems smaller today.