Paul, this is John.

John, this is Paul. 
1. Have you met Paul?

No, I haven't. 
Paul, this is John.

John, this is Paul.

2. Have you two met each other?

Have you two met each other? 
No, we haven't. 
Anne, this is Marie.

Marie, Anne. 
 

Have you two met each other? 
Yes, we have.