look up any word, like dirty sanchez:
 
1.
putting ones testicals into a girls anus and then masturbating then ejaculating onto her back.
man me n this female where getting down, next thing i know i was copping two in one
by clickyray June 22, 2008
 
2.
masturbating while taking a poop
jay pulled a twoinone at his girlfriends grandmas house
by warhero87 April 04, 2010
 
3.
Its 2 nipples in one ariola
zach has a twoinone
by TheKidInYourMom December 08, 2010