When suggesting that someone consider entering into a relationship with someone else, one must be mindful of the commandment before a blind person do not place a stumbling block (Vayikra 19:14), which our sages interpret as an admonition not to offer advice which is not proper. It is absolutely forbidden to suggest someone as a possible employee, business partner or marriage partner if one is aware that:Objectively speaking, it may not be good for the people involved.

(Taken from the Sefer Shmiras Halashon, Chofetz Chaim A Lesson A Day – Day 81 pg. 212)