A nest egg

[Ferb]

A husband and wife are moving out of their house and are starting to box everything up.
The husband finds a box under the bed, pulls it out, and looks inside, where he finds two eggs and about £8,000.
He approaches the wife and asks,
"What are the eggs for?"
She replies, "Every time I cheat on you, I put an egg in the box."
He says, "That's alright, you've only cheated on me twice.
What's the money for?"
The wife replies, "Every time I get a dozen, I sell them!"

[Techno]

Dearie, dearie me ! 
Cheers - Phil

[FierceKitty]

Economically dubious. To make that kind of profit on small-scale egg sales she'd need to be running a brothel herself, no matter how lively she was between the sheets.