haha, she wasn't gonna tell ya cause you prolly have gone crazy over shit like that before.
personally i hate people like that (not saying you are), some people have weird "things" about them when it comes to stuff like that... for example, if someone spills something, even if its water, they'll go crazy about it and won't shut the fuck up (my brother inlaw for one).
best thing to do when someone does something accidental is not to go insane about it cause it wont help the situation or any other future accidents.
but yeah, be mad if she didn't tell you about it and had no reason not to tell ya.
