What are these two up to?

Wife was away overnight as she was climbing on The Roaches today. It would have been nice to have the day to myself but son and granddaughter were here but I still managed a few short sessions for a blip image. The one I have chosen came mid-afternoon when I walked the garden with the dogs. As I passed the raspberries I noticed a couple of white butterflies swooping around. One of them landed on a leaf and shortly after the second one started fluttering around it whilst the one on the leaf stayed still – I can’t think what they were up to!