1001st base 

When two men clip open their ball sacks, allowing their nuts to fall out and dangle on your eyelids as you orgasm.

Chris: Hey, Katherine.
Katherine: Hi, Chris!
Chris: I 1001st base'd last night!
Katherine: Holy.. fuck..

1001st base by ChrisRawr June 2, 2013

101st base 

When you have sex with a female while she is menstruating and the guy is doing a shit and getting mess all over the place.

guy 1: omg man i got to 101st base with my girlfriend last name

guy 2: *throws up*

101st base by Jubz! October 25, 2006