Halacha 3: Makes no difference if you spoke rechilus to the subject himself or to his relatives, even if you tell them to keep it a secret because they will still get angry and bear a grudge against someone who said or did something to his or her relative. Surely to not tell them to keep it a secret is forbidden because word spreads and the subject will find out and fights will escalate but even if they won’t tell him, it’s forbidden whether it’s an outright negative statement or it can be taken either way, telling the relatives we can assume the relatives will take a negative slant and defend their family. However, if you tell a total stranger what someone did to someone else and tell him to keep it a secret that is fine because nothing can escalate.
Halacha 4: Rechilus is a problem whether you are telling on a Jew to another or to a non-Jew and it’s even worse telling a non-Jew because no doubt he will cause trouble for the would be suspect and might even be life threatening. This means even telling a non-Jew that this Jewish prodect you bought isn’t so good or the job the Jew did for you wasn’t a great job and the like. However, if it is really true that the Jew sold the non-Jew something broken or really did a terrible job the there is an obligation to tell the non-Jew based on the pasuk of “righteousness, righteousness you shall run after” (Devarim 16:20). The Jews are holy; just and upright, therefore we have to adhere to doing the right thing and if one of us did wrong even to a non-Jew we can’t cover it up. However, if the matter is relative or false then it is certainly rechilus.
Halacha 5: You can’t accept rechilus from anyone just like lashon hara even from your wife. It’s extra critical when your wife is telling you about her day, she is allowed to vent but if she starts telling you how she heard how someone said something or did something not nice to you then you can’t show your interest in what she is saying and you should politely and nicely show your disinterest and figure out a way to nicely tell her you don’t want to here about it. This is because what she is saying is rechilus and if you agreeably listen now she will speak rechilus again some other time and it will cause a lot of anger, frustration, arguments and eventually depression.