That is my idea of a fantasy come true! You are a lucky lucky man. My best ever fuck was when i was 19 and the granny was 51. Still wank over her daily.
I am fortunate enough to live with two mature women both 40+. I am 26 and we been together for 6 year's. And the best part is they share me with their Lady friends the oldest being 60 years old. Always a great time and I am never hard up.