One defence to possession and making child pornography crimes is the 'private use exception.'
Two things are allowed under this exception:
Expressive material created and held by a single person and meant for their eyes only, such as personal journals and drawings.
Consensual, private recordings of lawful sexual activity created and held exclusively for private use and with the consent of everyone recorded.
Non consensual sexual activity is not lawful, and the private use exception does not apply to it. For example, sexual activity with someone under 16 years of age is sexual interference (unless the close in age exception applies), which is a crime. Similarly, sexual activity between a 16- or 17-year-old and someone in a position of authority over them is sexual exploitation – another crime.
The private use exception cannot be used for the distribution of child pornography. As soon as someone sends the child pornography to someone else, they cannot rely on the private use exception and are liable for child pornography offences.
As soon as someone using the private use exception intends to use the child pornography for anything other than their own private use, they have committed a child pornography crime. Threatening to show the recording to others can be evidence of that intention used to prove an accused guilty.
A person in the recording has the right to demand that the recording be returned to them or destroyed at any time. Consent to record is not consent to keep the recording.