The jacket was bought for some sequences in the film, London Dreams, but Salman fell in love with the jacket, so much so, that he wanted to wear it in scenes, which didn't require him to do so.
He was seen sporting it even when the shooting wasn't on, much to the amusement of the film unit.
According to Vipul, Salman loves stylish clothes and he liked the jacket a lot. So, finally, Vipul decided to gift it to him, as a small token.