Are there unspoken rules for Snapchat?

I don't really like snapchat, but it's kind of addictive. I dont have very many followers... less than 20. Just a few people I went to HS with or worked with in the last few years. I'm just curious if there are any unspoken rules of snapchat? Like I'm looking at the adorable face of my SO sleeping next to me and I'd love to capture his sweet face and snapchat it, but would that be weird? What can snapchat and what can you not snapchat? The social anxiety this app gives me is seriously annoying lol