Ace coded means: Describing someone or a fictional character who reads as asexual or aromantic based on their vibe, behavior, or how they engage with romance - even without explicit confirmation. Widely used in fan. It carries sexual or vulgar connotations; not alarming on its own but worth understanding the context your teen heard it in. 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.