The Daily Mail online had reported that an Ugandan man got married to three wives at the same time and on the same day. Two of his wives happened to be sisters. Click here to read the news on the Daily Mail online.
Originally, as long as all co-wives do agree and are happy with their polygamous arrangement, other people would better remain silent even if they disagree with them.
However, Islamic rules about whom one can be married to aren’t a matter of agreeing and disagreeing, they’re a matter of borderlines that GOD has defined and that no one should trespass.
To be married to two sisters at the same time is forbidden by the words of Quran and when Prophet Muhammad chose Othman ibn Affan to give him his two daughters in marriage, he never gave them to him simultaneously. Othman got married to Roqayya first and when she died, he became deeply sad. So, Muhammad soothed Othman’s sadness by giving him her younger sister, Umm Kulthoum, who was much like Roqayya.
The same thing happened to Prophet Muhammad : he got married to Zaynab bint Khuzayma who was renowned by Mother of the poor because she was extremely kind to poor people. Zaynab died several months after marriage then, years later, Muhammad got married to her maternal sister, Maymunah bint al-Harith.
No marriage with a second sister would have taken place if a husband was still married to the first sister. Definitely.