To shit one's pants.

To engage in anal intercourse. To stick ones penis in anothers butt.

Participating in anal sex.

When a man or women or man and man are having anal sex and during the anal penetration, the women or other man shits onto the penis.

When a man reaches into his anus and pulls out his intestinal lining. He then inserts his penis into the “casing” and stimulates his penis.