beat a dead horse
have ants in your pants
be a fish out of water
be a guinea pig
have butterflies in your stomach
clam up
get off your high horse
be in the doghouse
stop being superior
not fit in, be out of place
be in trouble
be anxious or excited to do something
not say anything, perhaps because you feel uncomfortable
waste your time on something
be the subject of an experiment
be nervous
