Its used a few ways. Eg. 'That cheeky little boy!' Kinda like what rina said naughty etc. Can be used in a kinky way also, or say someones wearing really short shorts and their cheeks are hanging out :lol: come to think of it its basically just naughty but used in different ways :lol:
its hard to explain, Can mean mischievous, like a clean way. So just cheeky. Or the dirty version and yeah.
I use it more as a term of endearment, like when a kid or animal does something naughty, but they're just too damn cute to be mad at.. That's cheeky lol