Don't hide it is the best advice I can give. Withholding is a form of lying and people can see through it.
If someone is brave enough to broach the subject or simply ask about you and your W, a good way to approach it is head on, with as few words as possible:
Them: "So how are things with you and your W?"
You: "We've hit a rough patch. I would rather not talk about it, due to the personal nature."
Leave it at that. If they press, hold your ground and physically leave their company if they will not respect your boundaries.
Anything you might say could be interpreted differently than you intended and shared without your consent which can have negative consequences.
That's not to say that you might want to share. Know who you can trust and share only positive as much as possible. Conduct yourself with solutions based mentality. If any chosen friend you share with cannot support your pro-M discussion, then stop sharing with them.
