The expression above is spoken by Hardcastle right after Marlow comes to ask for forgiveness for the way in which he acted toward Hardcastle. Remember that Marlow was fooled by being told that the Hardcastle house was a local inn and that the man of the house was basically nothing but an innkeeper. As a result, Marlow was brash with he, who would soon become his father in law.
After Marlow realizes his mistake and asks for Hardcastle's forgiveness he also questions him about how his own reaction toward Hardcastles's daughter, his soon to be fiancee, may have influenced the family as a whole. Marlow had behaved extremely odd with Kate upon their first meeting because he has an issue with women of his own class; he gets scared and shy to the point of hardly even looking at Kate's face. However, when Kate notices this she later on pretends to be a barmaid (stooping low as a lower-class woman) to make Marlow feel comfortable and open toward her. This allowed Kate to understand Marlow's personality.
Since Marlow is aware of how ackward the whole thing has been, he is afraid that he may have lost his chances with Kate, for which her father answers
Girls like to be played with, and rumpled a little too, sometimes
What he means by this is that women sometimes enjoy the challenge of a man who treats them in a way that may otherwise upset them (like to be played with). We know that Kate is a good example of this.
He also says that girls like to be "rumpled". To be rumpled in the literary sense is impossible, for you can only rumple something that can be creased, such as a piece of paper, or cloth, etc. Hence, what he means is that sometimes even when a man bothers or upsets a woman to the point of really disarming her is alright as long as it only happens "sometimes".