I think an open marriage is an even unhealthier environment for kids than divorce. One minute mummy and daddy are together-everything is fine-the next daddy got his mistress pregnant, mummy caught HIV and were gonna have a new brother/sister in 9months that we only see 3 times a week...
Seriously?? Its healthier to say-mummy and daddy are not happy living together anymore coz sometimes adults grow apart but we will both always love you no matter what and we will both always be a part of your life.. bring them to a family counsellor and make the divorce amicable and friendly-share custody
If its done the right way, then it can be fine on the kids. Its not fine when they see there parents fighting like cat and dog and then are introduced to a new lover a week later.. who replaces them
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Ill add: your wife doesnt love you anymore-the emotional intimacy is not there which is why she is turned off sex with you. And the fact she said she never wants sex again gives you a definate answer-no counselling wont fix it
And if you have an open marriage-its only a matter of time before one of you falls in love which makes a divorce inevitable so why pro-long it?