This actually happened about 2 years ago during my youth service. This woman was my landlady, and she also lived in the same compound with us. She was in her 40s.
One day, she was outside washing clothes and bent down. She had a very big ass even bigger than what some ladies in their 20s have. As I was passing by, I got hard immediately, so I greeted her, not knowing she had already noticed me looking at her ass and saw how hard I was.
Then the next day, while I was at home in the afternoon, someone knocked on my door. I was surprised to see that it was her. She started explaining that she noticed how hard I got the previous day when I saw her. One thing led to another, and we ended up having sฤx. She even promised me a huge amount of money too ๐
Since then, it became a normal thing between us until I finished my youth service.