Under a comment that someone mentioned their own disability
The subreddit dedicated to the one-joke. To simplify the one-joke is a joke used to stereotype trans people and make fun of them. Often it's formatted as, "My pronouns are (Object/Object)", "I identify as (Object)", "Did you just assume my gender", and similar. Not all jokes regarding to trans people are the one-joke. The one joke does not have to be malicious and can also be satirical and funny at times
