@ArcticSkewer
There isn't any particular reason to think that leaving because of a poor sex life is going to be any more or less civil than leaving because one partner found other sex partners and the other partner decided they didn't like that after all.
Yes there is. And it wouldn't be just a case of 'deciding they didn't like it. No doubt there would be an incredible amount of hurt and pain and anger.
A man who doesn't like his wife sleeping with other people but also doesn't want to sleep with her himself is hardly reasonable to begin with, but there's nothing to say things would turn toxic.
That's why I asked if he was depressed, he sounds passive and defeated. That's more likely than him being unreasonable.
And saying there's nothing to say things would turn toxic is just ridiculous, there is a very high chance that it would, the vast majority who have successful open relationships say that they only work for specific people with specific relationships and the rest fail catastrophically.
If you ever take a look on reddit at the dead bedrooms sub where people have tried this there's only a very rare person who said it worked for them, everyone else said it was a disaster which magnified their problems further and they regretted them.
Op knows her marriage and husband best. If she thinks her sex life with him can be resurrected to something vaguely satisfying to her, then great, wait it out if she wants to. He doesn't sound that invested in changing his libido, that's all. The big clue being agreeing she can sleep with other people rather than him do it. I wouldn't waste my time these days on trying to change someone else's libido.
OP said she has never been like this before. So her having this kind of libido is new. Her husband is possibly depressed, or just exhausted with the kids.
OPs libido changed. And OPs libido could possibly change again in a few months for all she knows.