Interesting, a "What If?" scenario with hypnotic milk instead of pheromones or cum (or maybe it's a side-story?). It's probably only going to involve her dominating other women either way, though.
It's explained in the novelization, which is complete, the Phoenix Force, unlocked by the villain protagonist, allows Jean to alter her physiology to take on attributes of his powers.
Thanks for the update, do you have "Jessica Rabbit Impreg"? Would you be willing to upload it in the future? I'm just wondering if anyone would be willing to share it, so if you have it and you're willing to upload it I'd be willing to wait a few months