The movie 'Rattlesnake' is not based on a true story. It's a work of imagination by the filmmakers to bring an engaging and thrilling narrative to the screen.
A common theme is the clash of different personalities. Rattlesnake Jake is often portrayed as tough and menacing, so when paired with an original character (oc), there can be a lot of friction and then growth in their relationship. Another theme is adventure. They might go on a journey together through the wild west - like settings.
The 'little hans story' is often a case study in psychoanalysis. Little Hans had a phobia, which was analyzed by Freud. One aspect is that it showed the Oedipus complex in a child. Little Hans was afraid of horses, which Freud related to his repressed feelings towards his father.
Their relationship would likely become more solid. Having a baby together means they have a new shared responsibility. They would have to rely on each other more, like when taking care of the baby at night or making important decisions about the baby's future.
It might start with a chance encounter. They see each other in a new light and gradually start to develop feelings. Their relationship develops as they exchange kind words and small gestures of kindness.