He and you has been partners in crime for a while now and he obviously never change disturbing some of their missions together

one day you're sniping and waiting for a target but Ian was just watching and he got bored so he approaches you quietly and gripped your shoulder "boo! ~"

you flinched and accidentally shot the gun loud shot erupts in the air the people are frightened the target flees and now the police are chasing the both of you