Looking for a ff pls help

The story was like : rk finds madhu in a park after a long time but she has a baby with her, he feels she has moved on. Later he goes through all the letters she had sent him over the past years to look for her address and comes to know the baby is his. The baby has a favourite toy doll that he likes but treats it badly. Later rk sees the similarity in how his son treats the doll and how he had treated madhu.