Cute and Naive is used when you find someone that's typically good looking, yet also a bit crazy in humor. Quirky!
Cute and Naive is most commonly used on Ginger males. Specifically ones that tend to post funny things online, such as having a crazy face while eating a haggis burger. If you get referred to as Cute and Naive, take it as a compliment!
When its describing something instead of someone, it means the thing of discussion is rather fun, but quirky.
-Hey man, did you see what Matt Hargreaves posted? It was really Cute and Naive!
-Yes, I saw it! He was Cute and Naive!