We have set up trusts for our Ds that are protected from a divorce. However, if the Ds get disbursements from the trust and co-mingle it with their SOs, the co-mingled funds are community property. I’m okay with that. Marriage is a partnership and shouldn’t be 100% this is mine/that is yours. We feel that the way it’s set up, it takes some thought (and for a while, a trustee) to disburse funds, so opportunity for reflection is always there.
In the situation described, sounds like a pre-nup might be in order if the participants have any concerns about inequity of proceeds later.