A sexual act that is performed by placing the penis inside of the vagina and not performing any further action. It is customary to set up a buffet table next to the bed so that neither party becomes hungry during the often hours-long ordeal. One is not allowed to call or text while sheathing, as sheathing is the ultimate sign of commitment towards a sexual partner. It is perfectly fine to sleep while sheathing. The sheathing ends when: the penis becomes pruned; either party has to urinate, because the result of urination while sheathing would be like putting a thumb over a hose; death of either party; the end of the relationship between the parties. It is not permissible to orgasm while sheathing.

when you're hungover as shit after a spending a night drunk as a skunk

The act of giving a handjob to an uncircumcised penis.

The act of inserting one's erect penis into another larger penis.