A jewish shower is a sex position in which two people allign in a reverse 69 position, and proceed to fart for as long as possible while in this position.
Note: It may be helpful to eat taco bell before attempting a Jewish Shower
Hey bill, what did you and susie get up to last night?
Well, I heard her mom was Jewish so I gave her a Jewish shower...
Not referring to an actual shower, "Sin Shower" is actually a term of endearment used for friend rituals. Such as when everyone is drunk as fuck or some idiots decide to hot box a tent their friend's parents need to use the next day.
Person A: "Dude, what happened yesterday?"
Person B: "It was one hell of a Sin Shower"
OR
Person A: "You know... I love you guys" *cries like a little bitch*
Person B: "Friends that Sin Shower together, stay together"
Karl: "Wtf is a Sin Shower"
Person B: "STFU KARL"
The false shower piss is when one is standing in a shower under the water and the water goes down ones body and falls of the shlong (penis) and creates the sound of as if one is pissing hence the name false shower piss
Person 1: *through the door* are you pissing in the shower?
Person 2: *in the shower* no its the false shower piss