Not yours to share
I
Freshman year I lived in a dorm suite with 4 other freshmen. Our suite had enough space to set up a TV and Wii U, so A, a friend also studying the same year at the school of business, would regularly come over to smoke weed and play Super Smash Bros. A pretty good time overall - I remember betting 2 whole wafers I could beat A 1-on-1 without losing any of my 3 lives, a loss from which I have yet to recover.
Situated near a weed shop and home to Green Wolverine, the school of business seems open enough to weed. One day after class I joined A in a group conversation and joked about A's smoking weed. A didn't respond. I figured they didn't hear, so I repeated the joke. Still no response. I tried a third time, and
“Could you please stop joking about weed? I thought you would take the hint or drop it if I ignored the joke. Some of the upperclassmen in my club don't really approve of weed, and they could've overheard your joke.”
Shame washed over me. I pushed back a bit in my head, something about owning up to your actions. However, I knew A had it right. Even if A had openly smoked in front of me, I shouldn't've openly shared that fact at risk of A's reputation.
II
“Actually, not-quite-an-expert, I know a few gay people.”
“Really, B, who?”
I expected B to list roles, e.g. “my coworker” or “my cousin.” To my surprise, B listed some names.
“Hold on, B. I'm going to forget those names. I don't think you should share by name.”
“Oh, don't worry. They're open about being gay. And we're in New York, so people around us are pretty accepting of it.”
“Ok sure. But even if 99% of the time people are okay with it, or even positive about it, that 1% of time where someone would be visibly or silently harmful isn't your risk to take. It's not your information to share.”
B paused. I could tell they understood, and we switched back to the previous topic of conversation.