The Question: The inquirer’s 15-year old son is dating a 15-year-old girl. The parents just found out that the girl’s parents, who are immigrants and from another culture, do not want their daughter dating yet. The boy’s parents want to know if they should tell the girls’ parents about the relationship or, perhaps, tell their son not to date her. The ultimate question: “I’m worried I could get my son’s girlfriend in big trouble or even put her in danger. Can I just supervise them at my house and absolve myself of enforcing her parents’ rules?”
The Shortest Answer from Ethics Alarms: No.
The Slightly Longer Answer from Ethics Alarms : It’s the Golden Rule, dummy!
The More Detailed Answer: Tell your son that he may not continue dating the girl against the will of her parents, and that if he does, you will be forced to blow the whistle on her.
Oh yeah, one more thing: Remind your son the “Romeo and Juliet” is just a play.
[I didn’t even bother to read The Ethicist’s answer before I wrote this when I saw that Prof. Appiah took over 500 words to explain the easiest of ethics calls. I did notice that he mentioned “Romeo and Juliet,” however.]
Ethics Alarms 
Question: Are the two set of parents close enough friends that they actually talk regularly?
I’d look at this a bit differently.
1. The son is already dating the girl, therefore they are breaking the rule the girl’s parents are dictating.
2. You can tell the son that he can’t date the girl and you’ve done your job. Be really honest with yourself, the son and girl are already breaking the rules, do you honestly think that you telling the son they can’t date is going to change anything?
3. If the two sets of parents talk regularly or routinely then the two 15 year old teens need to fully understand that the subject IS going to come up at some point in time and the son’s parents will not lie about it, period.
4. The son needs to be told about the cultural differences and what can happen to a young girl if she breaks a rule such as this.
5. The son is already making choices and will continue to do so, so arm the son with additional information and allow him to make an informed choice about the relationship.
1.Question: Are the two set of parents close enough friends that they actually talk regularly? No, they don’t know each other. The girl’s parents barely speak English.
2. I thought about “the boy’s going to do what he wants regardless of what we say” problem, briefly. That’s the parent’s problem, and they have to deal with it. Same as if they found out he was using drugs, selling drugs, or shoplifting. They cab’t use “He won’t obey us” as an excuse not to do the right thing.
3. The son needs to be told about the cultural differences and what can happen to a young man if he helps her she break a rule such as this.