refer to situations or circumstances wherein you find yourself feeling awkward towards a person whom you don't know personally or you're not close to BECAUSE of something you know about him or her.

Situation:

Person A and Person B works for the same company. They know each other by face and name.
Person C is the bestfriend of Person A.

Person C tells Person A that Person B is actually THE ex-girlfriend or ex-lover of her current boyfriend whom she suspects is still madly in love with Person B.
One morning, Person A meets Person B in the comfort room of the office and there was awkward silence.