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2.
What's this?
"Fred drunkenly pulled down the transsexual's skirt, mumbling, 'umm stiss?'"
by Professor Plum July 08, 2003
 
1.
when you stroke your penis up and down it makes an umm - stiss sound
he was beating his penis in the bathroom and you could hear an umm stiss sound from the next room
by Anonymous March 30, 2003