Are you referring to Avrohom Avinu? Yaakov Avinu?
Leah Imeinu, and the other Imahos, had no qualms. In fact, Sarah Imeinu is the one who suggested to Avrohom Avinu to take a second wife!
BTW, I recall reading a post by “haifagirl” in the Coffee Room here, that she wouldn’t mind marrying someone who already had a wife.