they are my friends for more than two years. well, i just knew their other friends for a month. we've hung out, talk etc. but what i don't understand is that they call me silent killer (i can't distinguish it wether it's sarcastic or not) because i laugh with no sound, i don't open myself much to them cause we just knew each other, and i'm a bit distant "I told you (my friend's name), (my name) is a silent killer"