Bad Student gets lucky

I left school at 15, I wasn't any good and started to learn a trade (mechanic) which I have done well at. Then at 23 I net my old math's teacher 53, just by chance in carpark of the supermarket, she was having car problems. I got it started and told her it needed a good servicing more than anything else. But teachers don't get paid well in these parts, but I had always liked her as a teacher and so I said I would do it for her the next day Sunday. I went over in the morning about 9 and done the servicing, I was on break down duty and had the work truck. Which made doing the servicing easier, the car was easy to get back to reliable state. She offered to make me dinner as a thank you, but I got called away. I saw her again the following Saturday and she said she owed me a dinner and asked when I could come by. Tonight, or tomorrow night I've nothing planned I answered. Tonight, it is she said, and we parted ways. I arrived over place about 6 and we talked a bit before dinner and after I helped her clean up. I was thinking of leaving and she asked me did I have a girlfriend and I said no, I don't do well in relationships so am usually free most weekends. To my great surprise she asked me straight out about fucking her. I was shocked, but it soon passed, and I agreed, and I stayed the night. Sex between us became regular thing and I would get a message just saying tonight and I would reply with a thumb's up emoji or sad face emoji. Neither of us are in any personal relationships still 15 months of regular sex is a relationship of course a mutual benefit's relationship.