"Pyaar Ka Punchnama" star Kartik Aaryan, who improvised his lines while shooting for his forthcoming film "Guest Iin London", says improvising is natural for actors.Kartik said in a statement: "I love the comedy genre. It is such a good space to be in. I like that I have done films that make people laugh. Improvising is natural for any actor. We have ideas and share it with the director and if he likes it, it becomes part of the film."He will be seen with actor Paresh Rawal in the film. "Paresh ji has been more than amazing. His off-screen humour translates on-screen, and that is the best part about him. He even goes out of his way to help his co-stars deliver the best that they can. I'm so glad to have had him as my mentor on this comical journey called 'Guest Iin London'," Kartik said."Guest Iin London", directed by Ashwni Dhir, is slated to release on June 16.