@MusTheDataGuy It's not always clear whether somebody 'should' know something, even between two colleagues that are nominally in the same role, and assuming that something 'need not be said because it's commonly known / trivial' is such a classic and repeated cause of major miscommunication that it's better to be safe than sorry in these instances. — Bruno 1 min ago

Or the old cliché, “if I were to tell you, I’d have to kill you.” — WGroleau 1 min ago

@FailedScientist, your comment here is confusing as the question says "inter-faith marriage not gonna work". You were probably trying to refer only this situation, in which case, I think the question should be rephrased. Plus, in general, given the issues with have in the world, I would promote inter-faith alliances if I got a chance. You are trying to help your friend I'm sure. But if I were you, I would help the friend understand and prepare for future if I could. "I suggested her to revise her decision to marry a Muslim as it's not going to work" - You don't know that for sure. — KNP 47 secs ago