Hi all - My STBX and I (married 12 years) are discussing the separation agreement and are just starting to talk to lawyers (we are separated now 5 months). They are claiming that they are entitled to compensation for the hypothetical share of my parents' estates (who are not rich, but I will likely inherit in the six-figures at some point when they pass, provided my parents don't get too sick or have other unexpected expenses) that they would not receive if we divorce.

Is this a legitimate claim and are there any precedents for counterarguments? It seems pretty farfetched to assume that nobody will have medical costs, that my siblings won't need extra help, and that there could be a way to legitimately estimate my parents' net worth at the time they die (and to know what my parents have in their wills about who gets what) etc.

Thank you for any advice