the russian underside is when your lady gets on top of you upside down and backwards and masturbates you with a 400 pound salmon while you masturbate her with a snow fox.
"Natascha, I think we need to spice up our love life"
"Boris, if you go to the fish store and get some salmon, we can do the Russian Underside and things will be so much hotter!"
"Boris, if you go to the fish store and get some salmon, we can do the Russian Underside and things will be so much hotter!"
by milkmaid604 June 13, 2007
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