Cheeky
British SlangDefinition
Playfully impudent or irreverent; can also describe a small, slightly naughty indulgence done casually or on a whim.
Examples
"He flashed a cheeky grin at the teacher and asked if they could skip the quiz."
"We nipped out for a cheeky pint after work."
"I treated myself to a cheeky takeaway on the way home."