look up any word, like fellated:
 
3.
a steam boat willie is when you find a homeless man and call him willie, place a captains hat on his head then he proceeds to shit a horrible homeless shit on your chest. while he does this you yell out loud "I I caption!"
hey girl I'm so in love with you. lets get crazy and do a steam boat willie together!
by syko_ January 30, 2009
 
1.
When a girl blows on a guy's penis after taking a drag from a cigarette and then proceeds to stick a finger in the guy's ass and yell choo choo while blowing and sucking on the penis!
Choo choo muthafucka that bitch totally gave me a steamboat willie and then I shit on her face!
by MTC's Pub featuring Johnny August 18, 2006
 
2.
when a person takes a shit on their partner's chest and smears it all the way down their body, while smoking a cigar (yelling choo-choo is optional)
Boyfriend: Hey babe, i'm kinda horny lets try a steamboat willie
Girlfriend: Okay i'll get the cubans
by BonerCoveredInShit September 10, 2009
 
4.
During the act of having anal sex with a woman while she has her period, one reaches under her to find the string of the tampon and gently tugs at it shouting, "Toot toot, Steamboat Willie".
"Dude, my girl is on the rag, so I guess I'll just have to play Steamboat Willie"
by SpartanAOD February 08, 2008