You mean multiple sex partners? They have that anyway.
It’s not the same. The big deal is having it legalized. To shove it in the mainstream society’s face. To make the mainstream society support it as a legitimate marriage with benefits.
“It is everlasting wrath. It would be dreadful to suffer this fierceness and wrath of Almighty God one moment; but you must suffer it to all eternity. There will be no end to this exquisite horrible misery. When you look forward, you shall see a long for ever, a boundless duration before you, which will swallow up your thoughts, and amaze your soul; and you will absolutely despair of ever having any deliverance, any end, any mitigation, any rest at all. You will know certainly that you must wear out long ages, millions of millions of ages, in wrestling and conflicting with this almighty merciless vengeance; and then when you have so done, when so many ages have actually been spent by you in this manner, you will know that all is but a point to what remains. So that your punishment will indeed be infinite. Oh, who can express what the state of a soul in such circumstances is! All that we can possibly say about it, gives but a very feeble, faint representation of it; it is inexpressible and inconceivable: For ‘who knows the power of God’s anger?’” - Jonathan Edwards