For some, the impulse to "peek" comes from a psychological desire for forbidden knowledge or a momentary rush of adrenaline.
If you receive a video or photo that depicts someone's private moment without their consent, delete it. Sharing it makes you a participant in the violation.
Focusing on building your own healthy relationships and personal goals is a far more rewarding use of time than looking through a keyhole into someone else's life.
Instead of focusing on the act of spying, it is far more productive to understand the importance of privacy, the psychological roots of such impulses, and how to maintain healthy boundaries in a digital age. The Psychology of Curiosity vs. Privacy