Y/n Potter/ Snape is 15 years old and Harry potters twin but James is not her dad Severus snape is. She was sent to live with snape after lily and James died. Snape didn't mind tho as he always loved y/n. Her and Harry always knew each other. Draco and y/n have been best friends for 15 years. Y/n has never been to school as Snape never let her but she finally convinced him. SMUT WARNING ⚠️