General cheekiness:
* Have a bit of lip: This implies being slightly disrespectful or sassy.
* Be a smart aleck: This implies being overly clever or sarcastic.
* Be a wise guy: Similar to "smart aleck," but often with a more playful tone.
* Have a chip on your shoulder: This suggests being quick to take offense or be argumentative.
* Be a bit of a handful: This implies being mischievous and difficult to manage.
* Be a sassy pants: This is a playful and informal way to describe someone who is cheeky and confident.
Specifically playful cheekiness:
* Be a bit of a wag: This describes someone who is playful and mischievous, especially with words.
* Be a bit of a joker: This suggests someone who likes to make jokes, even if they're a little bit cheeky.
* Be a bit of a tease: This implies playfully teasing someone, often in a flirty way.
* Have a bit of fun: This is a general term for being playful and lighthearted, which can sometimes involve being cheeky.
The best idiom to use depends on the specific context and the tone you want to convey.