[bineeshm]

Think the story from Meera's perspective..

..yet the whole theory is convoluted by the fact that she slept with Ashish on her own will and with this the plot lost the value as if she can sleep with some one for just sympathy ...

Two points,
1. She slept with Ashish on her own free will
2. She let that guy in train have sex with her, whereas Krish asked her to let him play/entice but implicitly no sex. But she allowed him to have his way with her,

On both occasion she found way to blame Krish that he isn't possessive of her enough, whereas Desai was too possessive of her. Having sex with the above both was with her free will and not pushed by Krish. Also, Desai was possessive of her because she is married to Krish & she is not his legally or ethically. So he have to work hard to prove his love/lust/possessiveness to her whereas the husband may need not show that much possessiveness as he believed she is playing along with him and she belongs to him. That possessiveness theory of Desai can be applied to all illicit relationships in the world. 
This story is somewhere a grey area between cuckold and swapping. It is not pure cuckold as Krish is not too comfortable when the relationship between Meera and male partners grow. It is not swapping as they never did with another couple.
Mildly put, Meera's attitude is 'Fun is mine, Blame is yours".