This female Orange Tip (Anthocharis cardamines) was trying to get on quietly with the job of laying eggs on garlic mustard at Rowney Warren but was being pestered by two males.
There is an orange egg in this picture too, which must have been laid a couple of days ago as they start out white.
She eventually got fed up and signalled them to go away by raising the abdomen. (Several butterfly species seem to use this method, especially the whites). It did the trick, they left immediately.