Can my wife use her boyfriend’s lawyer to represent her if that he knew that she as a married women was committing adultery with his previous client?

Adultery is not at issue in our no fault state, so I see no conflict of interest.

Yes. I don't believe there is a conflict of interest.

California is a "no fault" divorce state, so it doesn't matter if a spouse committed adultery or not. An attorney may represent the wife and her boyfriend in both of their respective family law cases as long as their interests are not adverse to each other and no confidential information is revealed. However, your question suggests there may be a potential conflict of interest if the wife were to be called as a witness in the boyfriend's case or vice versa. This information is general and should not be construed to constitute specific legal advice nor to create an attorney/client relationship.

Yes. There is no conflict of interest. The lawyer will not be a witness.

Yes, and the issue of adultery is irrelevant in California.

The best place to ask your question is to telephone the Florida State Bar and ask the ethics attorney.