[pinkpanther]

1)Morality 

2)Islam has dress code.Four wives are non maharam to each other.They should maintain minimum dress code which is covering whole body except face, hand,feet .

3)Allah command believers to marry for it’s benefits 
Morally, spiritually, socially, physically . Not to have group sex like Christian

In heaven, There is no lust and sex like in this world.

1 Corinthians 7:2 ESV 

But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.

How to group sex with 1 wife?

Are you sure there is no lust and sex in Muslim Jannah?

God's messenger said 'every man who is accepted into heaven by God will marry 72 women, two of them will be uri (female entities of heaven of divine beauty) and 70 inheritance from those who dwell in hell. All of them will have lustful organs and the man will have an eternal penile erection" (Sunan Ibn Majah, 39).