(Proverbial Meaning:)
1) Having a lot of sexual intercourse with a lot of different persons.
2) Being situated in a risky situation, where one mistake can be fatal.
(Literal Meanig:)
Dropping the soap in
prison. When you drop the soap in
prison and you pick it up, you're bending over, which is the perfect oppertunity for your fellow prisoners to take you from behind and penetrate you in an unpleasant
way.