Imagine Rachael as the Spider Queen and she just bends and manipulates people with the insect gene at her will. She uses Peter even though he tries to resist her, and she tries to make him her king but he refuses all her attempts. They feel drawn to each other maybe because he's Spider-Man and she's the Spider Queen but who really knows. She slightly starts to force him into a relationship with her that he denies but actually enjoys quite a bit.

It can get even weirder than that when they make out maybe they exchange a type of venom only the two of them are immune to. Maybe when Rachael feels ready to mate she's not the one that has the spider babies...