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1.
When you put your dick in your sister.
I'm so horny if I don't insis soon I think I'm going to explode.
by Sofa King We Todd Did March 14, 2007
8 1
 
2.
Term to describe when someone tries really hard but just cant get the job done.
Named after the semi-famous german Unreal Tournament player inSi.

It originates from the german Expression:
"inSi kann nix!!!" (which roughly means "inSi sucks!!!")

The 3 exclamation marks have to be used to put more emphasis on the message.
"Wow, koby failed to sink that Buzzer-Shot and the Lakers lost? He pulled a real inSi off right there."

"Honey, I know you tried your best and the potatos taste good,
but i think the meat is a bit of an inSi."
by dermeisterrr November 17, 2008
5 1