Personal Hole

5k, cis M/cis M. A professor of magical history, Jan Jeschek, modifies his younger lover's body - namely, replaces his original genitalia with a new set of equipment - for the pleasure of divulging him of its virginity and then, getting him pregnant. Size difference and age difference, body transformation, domination and submission, power dynamics, crying, overstimulation, dirty talk, daddy kink, impregnation, a snapshot of some pregnant sex.
Eager and enthusiastic consent throughout. No gendered terms are applied to the original or the new genitalia, and nor does this story contain feminine language such as "mother" or similar.