'Kyunki Saas Bhi Kabhi Bahu Thi' 18th April written update: Nandini follows Karan & discovers his shocking secret

'Kyunki Saas Bhi Kabhi Bahu Thi' begins when Pari opens up to Aryan and her painful past. Aryan sympathizes and asks about Ajay. Pari tells him that Ajay's family does not accept her.

Aryan shares his own sad story of separation. Aryan asks Pari what she would change if she could go back in time. Pari says she would not change anything. Aryan gets a call from Gautam. Gautam learns from Aryan that Pari is his friend. Gautam tells Aryan to keep watching his brother and tells him to stay updated about what is happening. Gautam gives Aryan permission to spend time with his sister.Meanwhile, Karan leaves to take a delivery, and Nandini follows him secretly.

Ritik's plan for Mihir and Tulsi

Ritik brings Mihir to a restaurant where Tulsi is also supposed to arrive. Ritik confirms that Tulsi is coming. Ritik tells Mihir that Tulsi is coming to the restaurant and reveals their plan to bring them closer. Ritik admits he is failing to convince Tulsi on his own. Mihir is thrilled as Tulsi agrees to go on a date with him. Mihir questions how this is possible. Ritik explains that Tulsi does not know Mihir will be there, and Mihir does not know Tulsi is coming.

Ritik tells Mihir that with his looks, he can impress anyone, and anything is possible. Ritik leaves. Mihir prays to God to bring Tulsi in a good mood.

The unexpected encounter

Tulsi arrives at the restaurant and sees Nandini following Karan. Tulsi feels confused. She decides to call Nandini, but Mihir suddenly appears from behind and tells her they have a date today. Mihir explains that the children planned their date. Tulsi refuses to go with him to the restaurant, but Mihir requests her to come.

Tulsi tries to tell him about what she saw with Nandini.

Aryan at Malabar Hills

Aryan arrives at Malabar Hills and goes to the same flat number that Gautam mentioned. He finds no one there and leaves. A lady then arrives at the same flat and enters it.

Concern grows

Mihir learns that Nandini was following Karan and cannot believe what is happening. Mihir tells Tulsi to call Nandini and find out what is going on. Tulsi tries calling Nandini, but she does not pick up.

Tulsi and Mihir become worried. Mihir calls Nandini, and this time she answers. Tulsi asks Nandini directly why she is following Karan. Nandini hangs up the call without answering anything.

Parth's jealousy

Parth becomes jealous seeing Vaishnavi talking too much with the contractor. Dev tells Parth to call the fire brigade because he is so jealous. Dev suggests Parth do something quickly, or someone else will take Vaishnavi away from him.

The devastating discovery

Nandini reaches Malabar Hills and sees Karan taking a cake to the building. Karan rings the bell and enters the flat. Nandini watches as Karan hugs a woman inside. She tries to take pictures, but her phone shuts down. Karan tells the woman to cut the cake, and Nandini sees him smiling happily with her. Nandini starts crying outside the gate. Karan walks to close the gate. Nandini feels completely betrayed and cheated.Precap: Tulsi appeals to Nandini to calm down, but Nandini demands a divorce from Karan immediately.