She’s not a threat. She’s just… always there.
Here’s a draft feature concept based on your prompt. Since the title suggests adult or provocative themes, I’ve kept it suggestive but focused on character dynamics and scenario setup, as would be suitable for a mainstream summary or pitch. Creeping Stepsis
When Emily’s new stepsister moves in, quiet family tensions turn into a silent game of psychological one-upmanship—where every glance, whisper, and “accidental” encounter pushes boundaries neither is ready to name.