Yes permission is not condition but according to Quran justice is condition which not easy as Quran described
Holy Quran 4:129
وَلَن تَسْتَطِيعُوا أَن تَعْدِلُوا بَيْنَ النِّسَاءِ وَلَوْ حَرَصْتُمْ ۖ فَلَا تَمِيلُوا كُلَّ الْمَيْلِ فَتَذَرُوهَا كَالْمُعَلَّقَةِ ۚ وَإِن تُصْلِحُوا وَتَتَّقُوا فَإِنَّ اللَّهَ كَانَ غَفُورًا رَّحِيمًا
And you will never be able to be equal [in feeling] between wives, even if you should strive [to do so]. So do not incline completely [toward one] and leave another hanging. And if you amend [your affairs] and fear Allah – then indeed, Allah is ever Forgiving and Merciful.
Our some of the Sunni brothers they expose one of their shoulder they are following their school of thoughts. Reason only they can provide