It could mean she still has strong feelings for you. Maybe she realizes that the connection between you two is special and she can't stay away.
Another possibility is that she is simply used to the comfort and familiarity of your relationship. It's like having a favorite place to go back to. The routine, the shared memories, and the emotional bond all draw her back. However, it's important to communicate with her to understand her true intentions.
One reason could be that she truly loves you deeply. Despite any issues or arguments, her love overcomes those obstacles and she keeps coming back. Another possibility is that she's comfortable with you and the relationship provides a sense of security that she doesn't want to lose. Maybe she also realizes that the connection you two share is special and she can't find the same with anyone else.
You should communicate openly with her. Ask her why she keeps coming back. It could be that there are things she wants to work on in the relationship. Listen to her thoughts and share your own as well.
Be cautious. You need to figure out her motives first. Don't just jump back into the relationship without thinking.
It's not entirely clear without more context. 'Keeps coming back' could imply a recurring theme or situation in a story related to sex, but it's very ambiguous.
She might keep coming back because she has unfinished business. Maybe there are unresolved emotions or issues in the relationship or situation described in the story.
She may find a sense of security in the relationship. If she feels safe, understood and accepted, she would be inclined to keep coming back. Also, if they have common interests and goals, it can be a big draw. For example, if they both love traveling and have plans to explore the world together, she would be eager to maintain the relationship. And of course, the quality of communication matters. If they can communicate openly and effectively, it helps to strengthen the relationship and makes her want to stay.
One possible reason could be a strong physical attraction. If the sexual experience is highly satisfying on a physical level, she might be drawn back for more. Another reason could be an emotional connection that has developed during the sexual encounters, even if it's not a traditional romantic relationship.
It might imply revisiting a conundrum or a tricky situation in the story that has the nature of a riddle. Say there was a character who left a cryptic message, and 'coming back to riddle in your story' would be to focus on that message again, perhaps to uncover its hidden meaning and how it affects the overall narrative.
She could be a former lover who still has feelings for the protagonist. Maybe they had a deep connection that she can't let go of easily.
Perhaps there are emotional undertones that she's not fully aware of. Maybe she has feelings for the other person on a deeper level, which is expressed through the physical act in the story.