Kill-a-Half-Hour Question

MONDAY 1/27: Experts have found that if you’re married, and you’ve got a big [BLANK], you are at a much higher risk of a divorce.  What?
MONDAY 1/27: Experts have found that if you’re married, and you’ve got a big [BLANK], you are at a much higher risk of a divorce. What?

Clues:  “Every day” and “In the car”
Answer: Commute to work.