Option Group Either or?

Okay lets see if I can explain this good enough lol.

I have two questions in an option group->
After Fact: (They can answer) Yes or No
Surprise: (they can answer) Yes or No

Simple right? Here comes the hard part. I need to set up the group so that If they answer Yes to After Fact- Surprise will be Yes. If they answer Yes to Surprise, After Fact can be No. And still need to be able answer No to both these questions.