...he looked at me, and smirked...I looked at him, smirking...

I truly believe that there is a gross overuse of the term “smirk” in writing today.

Definition: To smile in an affected, often offensively self-satisfied manner.

This is a smirk. 

Grin - Definition: To smile broadly, often baring the teeth, as in amusement, glee, embarrassment, or other strong emotion.

This is a grin. 

Leer - Definition: To look with a sidelong glance, indicative especially of ual desire or sly and malicious intent.

This is a leer.

Sneer - Definition: A contemptuous facial expression, sound, or statement.

This is a sneer.