This is a sample of the sort of odd scenario that can present itself in one of the most benign milieux... a pair of people sitting on a park bench. Take a look at Albee's The Zoo Story, for example.

A guy and a gal are sitting on a park bench.
He has the urge to give her a smooch. Ordinary situation, for sure.
Being a thinking fellow, he ponders his prospects — is she willing and interested? What can the poor fellow do to assure he won't be slapped?
He presents this rational and logical proposition to her:

The Park Bench Proposition:

"Right now," he says, "I'd like to give you a smooch — either I can just impulsively, it would seem, kiss you; the alternative? — I don't. So let's say the odds are fifty-fifty that I kiss you when I feel compelled to do so."
She's somewhat taken aback by his declaration, but not too much — after all, it is an ordinary enough situation: a guy and a gal sitting on a park bench.

"Now," he goes on, "Let's say that of the times I feel the urge to kiss you, and ask you if I can, you either say yes, or you say no. So let's assign the same probability: fifty percent of the times I ask you, you say yes.
"So that means that of the times I feel the urge to kiss you, half the time I do, and half of the times I ask you, you say yes, so that's seventy-five percent of the times I feel the urge. Are you following me?"

She nods, silently, intrigued.

"Now, let's say I'm a bit of a cad — can't deny it, it's certainly likely; after all, look at the topics I choose when sitting on a park bench with a gal I'm fond of? — but let's say that of the times I ask you if I can kiss you and you say no; half of those times I kiss you anyway. You follow? So each iteration of the situation, each layer, adds its own probability to the sum."

"Yes," she replies. "I can see where you're going with this: it's at 87.5% right now, and if you keep iterating it, you end up with a virtual certainty — in short order, the odds will be upwards of 96%, so you might as well kiss me."

Being a gentleman, he does.