About 15 years. For much of that time, while I was still working in London, I would see her twice a week, once in her massage shop for a massage (at her usual rate), and once in a coffee shop for English lessons (she's Chinese). After I retired, I still saw her every time I went in to London. For about the final five years, she would give me full service (without condom). The last time I saw her, she had retired, although she still gave me a massage. I haven't seen her for some time now (probably about a year).