A male teacher began working three years ago. In that time, there was a girl in the 11th grade in the APWH class he had. She was 17 at the time. There was nothing going on between them when she was in his class. She was his student, he was her teacher and there was no sense of attraction between them... not even a small twinge. It was purely appropriate and professional.
Three years later, he meets this girl in a store. She is no longer in high school and is now 20 years old. This time, when they meet in the 7-11 aisle, there is an attraction. The more they speak, the more they like each other in a less than professional ex-student/teacher way.
Would it be okay to call her? She's not a minor, she's not his student and this isn't an extension of anything inappropriate that happened when she was in school. Or is it still wrong because she is his ex-student?