I could deduce by his FACIAL expression
and body language that he was sad.
The Big Bang Theory Season 10, Episode 16
It requires 34 FACIAL muscles
and 112 postural muscles.
The Big Bang Theory Season 4, Episode 21
...and did so
using a stern FACIAL expression.
The Big Bang Theory Season 4, Episode 24
Forgive me.
I'm not adept at reading FACIAL cues.
The Big Bang Theory Season 3, Episode 4
I'm not the best at reading FACIAL cues,
but I can see that you're a little turned on.
The Big Bang Theory Season 8, Episode 8