The other day after a playdate with her best friend, Sister informed me that they had swapped underwear as proof of their friendship. Not clean underwear, but the underwear that they were both wearing at the time.
I'm going to pause here while you contemplate that.
I still can't decide which I think is more weird and unsanitary--Sister doing that, or me at the same age pricking my finger with a filthy safety pin retrieved from the bottom of my own best friend's mother's purse so that we could become blood sisters.
Maybe it's best not to think about it.