Hi,You have no obligation to tell anything to anyone.You are his doctor not hers,and you need to stay clear of those types of personal problems.If not you could end up in a Lawsuit.Good luck.
A physician can't give out ANY personal health information to anyone other than the person it belongs to, without written consent. At least, that's how it works in the US.
Your wording sounds like you might be from another country. If so, I don't know what your customs/culture dictates you to do.
I'm not sure of your question. You say he doesn't want you to tell his wife (I assume you're his physician), but then you say he wants you to persuade her to allow him to remarry. Are you asking if it is ethical not to tell his ex-wife, as he is remarring another person?