My dh's boss is getting married in a month here and we live not too far away and are invited. The boss and gf are totally loaded, house in London, NY, Bahamas type of thing, but very unaffected. They claim it is small and casual, but what does this mean? What is de rigeur for UK weddings this season and will I stand out as an outdated, living overseas, frump, if I go in my (new) Boden wrap dress???