Serial Chess

Last night the Boy tried to teach the Girl to play chess.  During the course of his instruction (which was not going that well) this exchange took place:

Boy: And now my guy is going to kill your guy.  (The Girl becomes upset and is about to start protesting).  But wait, Sis! Now your guy can kill that guy.

Girl: (quite properly) Oh! Thank you, Bubba. I've always wanted to kill someone.

Upon reflection, I do not think she got upset that her pawn was taken.  I think she was annoyed that the Boy was doing all the killing and she hadn't dont any yet.