I have the fantasm that, when a teenager, my mother descovers some erotic spanking related magazine in my bedroom and dcides to spank for real in order to make me quit this unsafe fantasy.

It sounds like you're exploring a fantasy that touches on themes of authority, discipline, and taboo. These themes can be common in many people's thoughts and fantasies. Engaging with fantasies can be a way to process feelings and desires, but it's important to remember that they remain within the realm of imagination. If you're comfortable discussing this further or exploring related themes, feel free to share!