Love on the Rocks!!! Love or Extramarrital Affair?

Whisky on the rocks sounds cool and actually cool but love its complicated. A real life story where Sanjib  meets Shipra and falls in luv, say first sight luv. He is good looking, good attitude, talks well everything sounds gud, he used to meet gal in terms of business and gal too was doing fine with his dealings and personality till one evening he proposed to her accepting that he is married. Shipra denied but maintained the frendly relationship. Even after years she maintains the frendship but Sanjib confessing of in luv more than before and he feels he has nothing for his wife besides for the namesake. So my question is how legal is this love? It is love from Sanjib which he forcefully and genuinely says or a merely another extra marrital affair and also Shipra who maintains the frendship is doing wright or wrong?

If marriage is all about pure love, a strong relationship between a husband and his wife then why the breach happens and love shifts to somebody else termed extra? the secret talk, the sharing of personal lives to somebody else, the emotions turned hatred..for your partner and that hatred creates space for someone else so strong that it become unbreakable.......