RDJ and Marisa Tomei really had an affair
According to a book that I purchased called Hollywood Nights the director states that RDJ and Tomei had an on set affair, which was great for the film because of the chemistry between the two.
However, RDJ was married and had a small child at home so he (Jewison) tried to keep the two of them apart, which didn't work. Their affair ended by the time the premiere happened and then RDJ had to be forced to attend the premiere by Jewison.
I bought the book in the discount bin at the big theater at the end of Sunset, I can't remember the name. It is full of all kinds of inside info. It was presented by Bravo Films, it's called Bravo Films/Wild Nights/25 Yrs of Hollywood Festivals
its about Cannes, Sundance etc
I gave her my heart and she gave me a pen