Not looking for advice, just need to vent. Or hear from those in the same boat. Or something.
After spending 2 or 3 hours with DH and my infant DS this weekend, FIL has decided that the kid is uncared for and has developmental delays. His basis for thinking so seems to be that the little guy wasn't smiling or babbling at him enough and appeared "sullen" and "disheveled". I wish I were exaggerating.
I'm actually a little proud of kiddo for not smiling at Grandpa. Maybe my kid's a better judge of character than I give him credit for

He smiles at strangers all the time.
DH knows intellectually that FIL is being a jerk, but not so much emotionally. FIL is actually one his more functional relatives.
How do I get through Thanksgiving weekend with this guy?