If Zoya and Ayaan choose to honor their vows to each other - that also means allowing past loves to move on with their own lives. Respecting vows should not just be words but have to translate into actions. For whatever period they are married to each other - it needs to be honest and faithful. And yes - pining for lost loves is kinna adultery too.
I might sound highly judgmental here but dishonesty and deceit grate on my nerves.