A Jynx will always have baby Smoochums, and Smoochums/Jynx are always female, so when you use a Jynx for breeding, you won't be getting any male babies. Babies are always the same species as their mother, (or if a Pokémon breeds with Ditto, than the baby will be the same gender as the non-Ditto parent.) and since Jynx are always female, and she doesn't have a male counterpart, you will always get a baby Smoochum when a Jynx is involved in the breeding.