Do You Have a Relationship Deal Breaker?

What's your deal breaker?
What's your deal breaker?
What's your deal breaker?
Relationship deal breakers -- we all have them to varying degrees. It seems that even celebrities have deal breakers. While a guest on Jimmy Fallon the other night, Gwen Stefani revealed that she almost ditched Blake Shelton because of a deal breaker. What could Blake do that could possibly warrant a deal breaker?