When someone chooses to void their bowels of fecal matter while taking a shower, usually the result of laziness. The defecator must then leave the feces in the tub for someone else to deal with in order for it to be a proper shower-plop.
Chris was running late for work and did a shower-plop to save time.
Navy man - Hey Tate bud g, hop in the navy shower with me
Tate - ok bud g coming now
(tate drops soap, Navy man bum fucks him hard and rough causing Tates ass to rupture giving him haemorroids)
You take a shower where it is extremelycold because you need to be more alert.
Dustin- I need to make some moves but I don't want to get up
Justin- I'll give you a meth head shower if you want (proceeding to dump a bucket of water on his head)