Well, the topic reminded me of when people have said that to me in the past and that made me angry, but that isn't your fault and it's not even a bad thing. It was refreshing for me to express my opinion on this topic. Accessing some internal anger isn't actually a bad thing in my mind. So I wasn't hurt by this topic, but let's pretend that somehow I was. There was no way you could have predicted that a topic as innocent as this one would upset anyone. You can't be held responsible for everyone else's triggers because honestly, doing that would be ridiculous. I mean, one of my biggest triggers is footsteps. I can't be upset or offended with people just for walking and I also can't expect people to shout "TRIGGER WARNING" before their heel hits the ground. (Actually that would be even more upsetting yet really funny to picture)

I'm not saying that life is triggering and therefore we on this site shouldn't bother with trigger labels. If this post were about something graphic or something conventionally triggering, then yeah you should warn people. I'm just saying that you can't blame yourself for bringing up an innocent topic and someone happens to get offended. That's on that person for projecting their issues onto the situation. I don't believe people have a right to not be offended anyway.

Anyway, I think you should ask your T for clarification. I would.