No. There is no State law that says a pastor cannot divulge information. There may be ecclesiastical ramifications for the pastor, but it's not illegal. There may be a cause of action for clergy malpractice, but it is not common in Wa. and you would have to show economic damages. Having an affair in Wa. state is legal and has no impact of divorce law.
The information is for general information purposes only. Nothing stated above should be taken as legal advice for any individual case or situation.