Proposing to a girl and her father saying they may propose to one of his relatives

Q: Someone asked my father to give my sister in marriage to his son. My father told him that it is probable that one of his sons proposes to marry the man's daughter and that there was no need to speak of it then. Thereafter, my father told my sister that so-and-so asked him to give her in marriage to his son, giving her the choice either to accept such a marriage offer or marry whomsoever she chooses. Anyway, my sister accepted such a marriage offer and we then married her to the man's son, imposing a Mahr (mandatory gift to a bride from her groom) equal to that of her peers. After a while, I decided to propose to marry the daughter of the same man who had before asked my father to give my sister in marriage to his son. Is it a Shighar marriage (exchange of daughters or sisters for marriage with no mandatory gift to a bride from her groom), bearing in mind that we would never have given my sister in marriage to such a person had she refused his marriage offer. Please, give me a Fatwa on this issue.

A: If the reality is as mentioned, it will not be Shighar so long as there is no previous arrangement. (Part No. 18; Page No. 429) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.