CHAZAL say that Rochel wasn’t going to tell Leah about the simanim between her and Yaackov because it was a LACK OF TZNIUS THAT THEY HAD A PRIVATE RELATIONSHIP.
Yes, but that was before they were married when you might argue that it might have been improper to have a private relationship.
Or are you implying that having a private relationship after marriage should also be kept secret? Should people not know that I’m married? Is it a lack of tznius if people know I have a wife? I would think so since your entire analogy is based on the fact that the very existence of a relationship (and not whether or not people know about it) is a lack of tznius.
The Wolf