"Accidental mating" refers to when two animals of the same species engage in reproductive activities without intentional or planned effort. It happens by chance, without any predetermined intention or purpose to reproduce. Full definition
This prevents accidental mating that would have dire consequences in a recently spayed dog. (napahumane.org)
Nor are puppies born of accidental matings so likely to have been given the expert attention of a very experienced dog breeder during the first few formative weeks of their lives. (doggytoggery.com)
The only exception whereby you can consider buying a bunny is when the pet owners have sterilised the parent rabbits after the litter was born in order to prevent future accidental mating. (petsmagazine.com.sg)