AF is a short form of as f, to emphasize the following statements, e.g. tired AF, hungry AF. It portrays deep feelings or overstatement during informal conversations. Although it is a common word amongst teenagers and adults, it is vulgar and unsuitable to use it with kids. It is important to note that parents need to be aware of the fact that children may come across it on social sites, which is why they should talk to them about proper language use and online behavior and discuss the issue without being judgmental.
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