He rushes upstairs to find his wife naked on the bed, sweating and panting.
"What's up?" he says.
"I'm having a heart attack" cries the woman.
He rushes downstairs to grab the phone, but just as he's dialling, his 4-year-old son comes up and says "Daddy! Daddy! Uncle Ted's hiding in your closet and he's got no clothes on!"
The guy slams the phone down and storms upstairs into the bedroom, past his screaming wife, and rips open the wardrobe door. Sure enough, there is his brother, totally naked, cowering on the closet floor.
"You absolute swine!" says the husband
Spoiler:
