"Unrequited love" is usually when one person loves another, but keeps it a secret because it is not reciprocated. Is there a phrase to describe a two-way unrequited love? For example, where two people love each other, but both think it is not reciprocated, so both keep it a secret? 

This is a very common plot line in TV shows. For example, in season 3 of *The Office (US)*, Jim and Pam are both in love, and are not involved in any other relationships, but are both afraid to say something out of fear of rejection. Is there an succinct way to describe situations like this?