Bypassing the middleman

Hello Rabbi
Reuven and Shimon wanted to have a Shabbat with friends and were looking for an apartment to rent for Shabbat.
Shimon called the realtor and the realtor sent him Yehuda’s number (owner of an apartment for rent).
Shimon remembered that Yehuda was a very good friend of Reuven and Yehuda and Shimon were upset that the connection between them was created by an intermediary. They thought that maybe it would be possible for Reuven to call Yehuda directly and they would close the deal without having to pay a brokerage fee.
Is this permissible from a halachic perspective? After all, if Reuven had remembered that Yehuda was renting out his apartment, he would clearly have called him without going through the intermediary.