I've heard my friend say "me matas con cuchillito de palo" to his kid and I cannot figure out what it means. (I've googled it, and naturally google results are all over the map.) Usually the kid is acting up, but the way my friend says it does not sound like he's scolding or angry, only fed up.
How do I interpret this? Sometimes I watch his kid for him. Is this appropriate for me to say? (Cute kid, but kind of a snot sometimes.)
Thank you for your help.