Porcelain Tuck 

When a male awakens with morning wood and goes to take a morning shit, he will often times need to urinate as well. To avoid urinating everywhere except in the toilet due to an erection, one must tuck his erect penis under the toilet seat to hold it down.

"Yo, I had the biggest morning wood today and I had to pull off a porcelain tuck."

Porcelain Tuck by Dr. JRal September 22, 2005