I spent a fair amount of time recently photographing insects - especially butterflies (there's more to come). I felt slightly voyeuristic zooming in on what I assume is a tender moment between these two.
The inner wing surface on these (ie the bit not shown on this photo) is a beautiful powder blue so I assumed they were a type of blue. [Edited to coorect id] My limited research (ok - a trip to http://www.bogbumper.blogspot.com/ yesterday) suggested they were in fact a pair of Brown Argus, however a bit more research revealed the Brown Argus is in fact (unsurprisingly) brown although its underside looks similar to the above. These are Common Blues.