to go to 4th base with a different woman (or man) in all 50 states.
You:50! I finally did 50th base!

Partner: I thought this was fourth base!

You: it is for you, but not for me!
by $#$^#@%!#@%&*? August 16, 2008
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Having sex to the point where you are so sore you can't move, then forcing yourself on top of your partner and bouncing up and down.
1st guy: "Dude I got to 50th base last night"
2nd guy: "I thought I heard you two screaming, but I had no idea."
1st guy: "Yeah I can't feel my junk now."
by Newlemming August 30, 2008
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