Smirk

Rory was the only one who had done the reading. Rory was glad to be sitting at the front of the class since smirking wouldn't have been appreciated by the others.

Smirk away, Rory. Smirk. A. Way. 

As they say, "To the person who did the homework go the privileges of smirking." 

Of course that isn't a very common expression.