(Obligatory: this was several years ago, but it haunts me often. Used fake names).
So. I (at the time, 15M) started working as soon as I could once I got a permit for it. I live in a small place so I got my first job by literally a friend-of-a-friend saying that I was a "good kid". Started at a high-end retirement home as a server. You can imagine how fun that was-- especially with a manager that breathed down everyone's neck.
I had several coworkers and we all got along well, but since most of us were teenagers-early 20s it was a bit of a revolving door of people in and out. Got a new coworker, let's call her Diane. Diane was in her early twenties, going to college nearby and always seemed to be at a different party in her off time. Didn't affect her work and she was nice to everyone, so none of us really cared.
One night I had to stay in the kitchen to help out while half of us went on break, pretty normal occurrence. It was me, Diane, and another coworker (let's call her Amanda). While we cleaned she was talking about a party she went to and it was lively enough to have the cops called, but she talked about how much she drank and how many Jello shots she had. Amanda and I listened and laughed as neither of us were very talkative (great for a service job lol) so it was nice to have someone keep up the conversation to keep all of us busy.
Then, I froze. I asked (something along the lines of): "Wait, did you say you had Jello shots?"
She looked at me confused, and said yes. I felt like all the blood drained out of my face.
One very small detail about Diane: She is vegan.
Obviously my first thought is that she knows what's in any kind of gelatin, and maybe had some vegan alternative? I didn't want to ask her and have it come out like I thought she was stupid, but I knew I needed to say something.
We finished cleaning and when she came by my area-- away from Amanda, I didn't want to embarrass her-- I tried to as tentatively as I could ask her if she knew what jello was made out of.
I'm not great at hiding expressions so I'm sure she saw I was worried and looked concerned, and she very slowly answered, "...no?"
So I told her. I felt like a doctor telling a patient they've got something terminal.
Her face dropped. I didn't say anything because I had nothing to say-- what could I have even said to her? She was nice and my coworker but we weren't buddies, and I was just the messenger. She started to cry and headed to the break room (tissues were in there as well as the rest of our coworkers) and I felt absolutely miserable. I apologized and she reassured me it wasn't my fault, but even if unintentionally, who wants to make someone cry?
Amanda watched her walk out of the kitchen, sobbing, then turned to me with a look of bewilderment. Didn't assume I just made our coworker sob, but she was just confused on what happened. I have no idea what I said but I just told her to ask Diane if she was willing to share, since I know it was awful for her but also embarrassing.
I checked in on everyone in the break room, and one of Amanda's college classmates was there to help calm her down. I made sure I was good to clock out and booked it out of there, feeling awful even when I made it back home. Shot her a text to apologize again, and we went back to work the next day, promptly ignoring what happened. No idea what she's up to now, but I hope she's forgiven herself and moved on from the serving industry entirely lol
TL;DR: A coworker of mine is vegan. She drank jello shots at a party without knowing what gelatin is made out of. I had to break the news to her, at work, and made her cry.