Wow, 'blood brothers' - does THAT bring back memories! If your neighborhood was weird, then so was mine! My best friend and I did the blood brothers thing (well, blood sisters) - it looked like a crime scene in her kitchen because neither of us could get our fingers to stop bleeding. Her mom freaked out when she got home from work and noticed a pile of bloody tissues in the garbage can.
Guess we cut a bit too deep - you can still see my scar, 30+ years later!