Its when you are having sex with a chick and she is riding you reverse cowgirl and shits on you with explosive diarrhea and it puddles in and around your belly button.
Dude, this whore I picked up on 82nd gave me an Oregon Mud Puddle so I made her give me a rusty trombone!
to explode ones bowels via diarrhea inside the upper tank part of the toilet. this is basically the same as an upper decker, except this fills the tank with pure diarrhea. this usually occurs after consuming large amounts of various spicy and/or ethnic foods.
i just ate some extremely spicy yellow curry from jafaars middle eastern authentic cuisine restaurant, and when i get the hot sweaty spicy shits, i'm going to totally Pakistani mud puddle justin's toilet.
while having anal sex with your partner, you proceed to urinate inside his/her butthole. Followed by removal of the penis and lying on the ground (preferably a solid and easy to clean surface) your partner still containing the urine inside them proceeds to deficate on your face.
When you have a girl on her back for anal intercourse, you pull out and rub your member on her belly button to make it brown then unload in her belly button. Hence the mud puddle.
Troy: So how did your date go with Mindy?
Ernie: I didn't think anything was going to happen but before I knew it she was on her back and I was giving her a Texas Mud Puddle.