i am elaborating the idea
partho and sumona get married without the consent of their parents ,sumona had to bear the brunt of being a kayasth as partho's family is against intercast marriage
sumona often takes help of tools when partho is out of station and fulfills her need ,this couple sometime sends their 7 years old kid to sumona's home so that they can utlize this time .
garvit and garima are mutually cheating with each other and are only with each other for money .
Avishek for a long time was out of money and job , his books were not being published ,this was the time he got Rohini's support emotionally and financially .These three couples will make kalyani grew in the relation by their own relation statistics . Malhar too will grow in this relation .