An unwritten rule of law that compels the gut-dropper to go no more than three bouts of shitting without taking a shower. The ratio is set such to allow for illness, camping, and general dirty arsed folk.
"I'm already on my third shower of the day. I knew I shouldn't have ordered that vindaloo"
"May I quickly use your shower? I went to that Brazilian All You Can Eat last night and I need to reset the shit/shower ratio"
"You shower quit a lot"
"Yeah, I'm lactose intolerant but still eat pizza"
"Your farts stink!"
"Yeah, sorry. I really need a shit but I'm at my limit with the shit/shower ratio and can't shower until the weekend"
The libido and penis dimensions required to penetrate her standing up in the shower. With sufficient length this passion requires only rocking up on one's toes and back to flat foot. With sufficient girth she'll tolerate the desire for position creativity.
Refreshed rigor and vitality especially with rapid refractory to resume penetration after many other locations in the post coitus shower .