Girija once told vikram that he is a good lover, but he cannot be good husband. With that statement she made it very clear that "A good lover cannot be a good husband always". Even if Girija fucks many men, she will never leave her husband or children as they are her world. Sex is just an enjoyment and she thinks she deserves it from someone and not necessarily from her husband.
Even after having the vikram "thaali" in her neck, bavani has never pronounced vikram as purushan. Though she feels that she is in love with vikram, she also knows that love has no future. She also knows that vikram can be good lover and not a good husband. Vikram proved the Girija statement right by allowing Shaam to fuck bavani. Vikram cannot be committed and perform the duties and resposibilities of a husband. He can just make love and keep the women happy.
Bavani just want to thank vikram by giving birth to his baby. As long as it goes, she wants to continue having sex with vikram without her husband knowing it and live a dual life. If relationship with vikram becomes sour or any danger comes for her marriage life, She will always prefer going back to her husband and son. They are her world and all her future lies with them. Life with vikram is only temporary and she wants to enjoy that to the fullest possible with the time permitted and live the rest of life with mohan with those memories. Unless mohan finds the affair and secret about second child, Bavani can continue her dual life with vikram happily.
Who knows this can also become a lifetime relationship if vikram becomes a family friend of Mohan and Bavani continues to keep the relationship under wraps without mohan knowing about their affair and second child.
Bavani knows that she is responsible for everything and she cannot blame anyone for whatever she has done. She also knows that sex is just part of the life and not the life itself. She know that social status and respect comes only being wife of legally married husband. Sex is just few minutes enjoyment and she will never think about betting it for her life. Therefore, she will never leave her husband or family for it.