Dont waorry. Hum hain na. See I am commenting after you.
Honestly if you ask me, Karthik should give Nandini a chance. He was responsible for bringing her here, though inadvertetly.
Suman should tell him the truth and move on. She has some one like Tanmay and its wonderful.
But let them clean their slates first and then beging afresh. I am sure nandi i will also change for the better, karthik will learn to love her and I am sure Tanmay Suman ko to apne palkon par rakhega.