"Our working relationship is not that amicable. When we work together, we fight more," Irrfan said at the trailer launch of 'Madaari'.
"(But) she is the best critique of my work. She has a better understanding of my performance. She has inborn talent.
"If she says it is a good performance, I blindly accept it. So she has been kind of an inspiration for me to shape me as an actor," said Irrfan.
The couple met each other while studying at the National School of Drama (NSD). Recently, Irrfan shared a 'throwback' picture of the two with friends at the institute. Sikdar has turned a producer with 'Madaari', a film directed by Nishikant Kamat.
She thanked another producer of the film, Shailesh Singh.
"It is very difficult today to find somebody to believe in something which is not told so much. So to think of an idea and get it to fruition on screen is a long journey and without Shailesh, I don't think we would have been able to do it," she said.
Sikdar came up with the story of the film along with Shailja Kejriwal, who has been credited as one of the producers of the film and also for the story.
"I am very proud of the story myself. Shailja and I worked together on it. It was just a seed. We worked for a year to come to Irrfan because Irrfan is very fussy about scripts. I see him rejecting at least two films every day. We were very nervous.
"Shailja did a bit of the narration, I did more of it, and then we had Ritesh (Shah) who wrote the screenplay and then we gave the final narration.
"He (Irrfan) read the story and said, 'I like it', which gave us the confidence to develop it," Sikdar added.
'Madaari' also stars Jimmy Sheirgill.