These two happy exhibitionists knowing each other in the biblical sense on on of our Snakeshead fritillaries are Scarlet lily beetles (Lilioceris lilii). Sadly they are major pests and will do a lot of damage to our lilies and fritillaries if left unchecked. We left them to do their doings one year and we lost most of our lilies. Their fun didn't last long - Once I took the photos, I squashed them. They are just the only garden pest we will actively seek and destroy.
For further information check these sources
Royal Horticultural Society
UK Safari
