Nanu came out of the washroom and laid down as he was overwhealmed as he first time acknowledged his love, his care for Ishu. He slept, unknown to the fact that all his confession was been recorded by someone. That person angrily went towards Abhi's room.

Meanwhile, in Abhi's Room
Abhi was staring at Ishu's pic. He got a call. He checked the caller id and cut the call. Again the phone ranged and he cut the call. This repeated 3 more times. Yes, the person who was calling Abhi was none other than Sid. Once again Abhi got a call and being frustrated, he picked it without even checking the caller id  and started shouting.

Abhi (angrily): What is your problem ha? Agar call cut kar raha hu to samajh nahi sakte ki mujhe tumse baat hi nahi karni hai? Nahi galti meri hai...

Person (cut him off angrily): Ha galti teri hi hai. Teri hi galti hai.

Abhi (shocked): Bantu?

Bantu (angrily): Ha mai. And why the hell are you not picking Arth's call? Tumhara masla kya hai? Problem kya hai teri? Bina baat ke kisisebhi gussa karta hai. Tujhe pata hai teri problem kya hai? Tu na jo log bharose ke layak nahi hai unpe aankh band karke bharosa karta hai aur jo layak hai, unpe kisi choti baadpe rishte tod deta hai. I know ki tu hurt hai ki Arth ne uski real identity tujhse chupayi but this is not the way you should treat him. Are ye kyu nahi sochta ki koi to vajah hogi isiliye chupaya hoga apna naam usne. Par nahi. Abhishek, usne sirf naam chupaya to tu usse rishta tod raha hai, par tu us insaan ka kya karega jissne tujhse teri puri jindagi chupayi hai? Uspe to tera behad bharosa aur pyaar hai. Par yaha Arth ne tujhse sirf uska naam kya chpaya tune to use paraya hi kardiya. Yaha tak ki use curse bola tune. Sharam nahi aayi tujhe ye bolte hue? Yahi dosti thi teri, yahi tha tera bhaichara? Agar aisa bhaichara ho, to mujhe bhi nahi banna tera bhai, nahi banna tera dost as Arth ka naam Sarthak nahi Siddharth hai ye mujhe pata tha. Na sirf mujhe balki Ishu ko tak pata tha. Aur ye Ishu ka decision tha ki Arth ka asli name tujhse chupaye. Aur rahi baat Ishu ke maut ki, to uska jimmedar Arth nahi balki koi aur hai. And ha, Ishu ka accident nahi hua tha, ye ek planned murder tha. Mai abhi teri room me hi aane wala tha ye sab batane par tab hi Arth ka phone aaya aur usne milne bulaya. Tujhe bhi call kar raha tha par tune uthaya nahi. Aur agar bhul gaye ho to yaad dilata hu. Arth ko tumhare twin ke baareme pata hai. Atleast uske liye to aao. Agar usse sacchi pyaar karte ho to hi aana. Address bheja hai.

Saying this, he ended the call leaving Abhi in utter shock. Abhi composed himself and checked the address. It was an appartment. He drove there as fast as he could and saw Sid and Bantu waiting for him at the gate.

Abhi: Ye ghar?

Sid: Mere mumma papa ka hai. Hum bachpan me yahi rehte the. Ab koi nahi rehta. Maine yahi bulaya tumhe as yaha humari baatein sunne wala koi nahi hoga. We can safely talk here.

Sid said being emotional. It was the same place where Sid and Abhi had spent their lovely days of life with their parents. It was the same place where they got seperated. Abhi frowned seeing Sid's eyes getting teared up at the word 'Hum'. They went inside and Sid opened the door of the flat. He had already slyly taken that key from his Nanu's drawer. As Sid opened the door, all the memories got freshed while Abhi frozed on his place.

Abhi: Ye ghar tumhara? Meri mumma ka ghar.

He was too choked upto speak. Sid understood his dilema. He kept his hand on Abhi's shoulder and took him in baby Sidshek's room. 

That's it
This is on request of Muskaan (sorry mention nahi ho raha tha)

And those who all thought that the person who recorded the confession was Sid, they are unfortunately wrong. It was Bantu who recorded it all.