fifty percent chance I fuck your wife
Refers to a situation upon which there is a statistically binary outcome in the opportunity to have sex with an attractive married woman.
Person A - How do I know if there's a fifty percent chance I fuck your wife?
Person B - It's cool with me as long as it's cool with her and I'm allowed to watch!
Person B - It's cool with me as long as it's cool with her and I'm allowed to watch!