MIL cut it all off

My boyfriends mom was watching my son while I went to work. While she was watching him she decided to give him his first hair cut (my son just turned 2) she didn’t call me, text me, didn’t ask me at all. She just shaved his head. I am very upset, but my boyfriend doesn’t see a problem with it. Am I in the wrong for being upset she cut all his hair off without asking me?