Fairy comment means: A sarcastic and humorous comment on a social media post that contains whimsical emojis, usually begining with supportive and kind words but ending with a jocular insult.. It is internet-era slang, commonly seen on TikTok, Discord, Reddit or X. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.