Commotion in the Apple Tree

Looking out of the window at lunch time I noticed 2 brown what I thought were butterflies fluttering round our Crab Apple tree. On closer inspection I realised they were actually male Vapourer Moths, and closer inspection of the leaves they were fluttering round revealed a flightless female Vapourer Moth. As I gently moved the top leaf one of the now 3 males shot between my fingers to the female and mated with her! (see extra).
Entomology is so fascinating.