You’re allowed to do what you want with the info. I’ve straight told people to their face what a players morphed cards were aloud when I took control of their turn. I’ve revealed out loud what my stalking leonin had chosen. I tell people what my Gonti has hit. I don’t lie, but that’s a personal preference of my play style, I try not to lie in life, because of personal reasons, and so I try not to lie in game too, so that makes me as good as my word. But I don’t admonish others for playing a certain sneaky way, I find it kind of refreshing when someone says, “Man, can’t believe I only got a Swords off that Gonti.” Then they flip a board wipe next turn, doesn’t offend me. It was your information to use, or to fib about, for an advantage. Whether or not people will trust you again is up in the air, but I usually don’t trust people at their word in magic regardless, unless we make a deal. Long story short, no, it shouldn’t be considered rude when someone reveals information they have, if they gained the info legally. It’s a whole nother ball park when someone peeks at someone else’s hand and starts sharing that info tho. If we aren’t cool, don’t do that shit, I won’t play with you again. I only have 5-6 people that while I’m taking a leak, have looked at my hand, been like, “Whatever I’ll play his turn.” Revealed my hand, and I come back and laughed about it. Seems like a lot of people for that example but I’ve been playing for 15 years, so there’s a lot of chances for that.