Senior year of high school I had a pretty light schedule aside from math (I had to pass the class or I would not graduate) the first teacher I had was great but was ill almost the entire semester I learned next to nothing from the substitute teachers struggled the whole semester and got a poor grade. The next semester (last semester of hs) I got moved to a different class and a new teacher who would ask me and only me really personal questions about my relationships in front of the entire classroom and sometimes she would get a little flirty and me being a huge flirt I'd flirt right back. She would ask things like "are you still seeing ___ (whoever I was messing around with at the time)" it was sorta awkward having my personal life aired out to the class but I was getting really good grades in her class and she really helped me catch up from the first semester so I just went with it. On my way out of there after school on the last day I was in her classroom for something alone and we were having a conversation. she was asking about my summer plans and where I was working then she mentioned she had some things she needed done around the house and if I needed a job and to call her.
I wasn't creeped out by it but I know people would consider it very creepy