In the novel he is a widower and has 3 concubines because he has not remarried (formally I mean). He has a rep of being a player. QX doesn't like him and avoids him, and this is before the whole painting fiasco. They do meet in a shop but instead of a jade bracelet for grandmother, the gift is something else. He doesn't do the hiding the gift thing like in the series, if I remember correctly. There is tension from the get go because he does fall for her, without knowing who she is, and then realizes she is WS's wife. I barely started the series, so I don't know how they handled the whole battle at the end, but in the book he does help by giving intelligence to QX which she passes on to grandmother.
If you want the exact chapters I have to go back to the novel and list them.