Okay, let me give an alternative situation then.
A 14 year old girl sends a sexual text message to her (also underage) boyfriend. In Minnesota, the 14-year-old-girl was charged with Child Pornography.
https://www.aclu.org/blog/juvenile-justice/minnesota-prosecu...
If you think morality is black-and-white, then you are going to cause issues to many people. There's nothing "black and white" about distributing child porn. There are unfortunately, a ton of gray areas.
Yes, there are clear-cut cases of CP that need to be banned. But you must ALWAYS be wary about the edge cases, lest you harm otherwise innocent people. A 14-year-old who sends naked pictures of herself to her friends is... well... objectionable, but it shouldn't result in a sex-crime on her permanent record.