Vow renewal surprise

“Hello, it's my parents 10 year anniversary next June. They always go away with my sister and my gran at the end of Maylbeginning of June (anniversary is 18th june) but are back home for their anniversary. However as a surprise myself and partner have booked to go on holiday and surprise them. Its in Alcudia, we are staing in seperate hotels but they are across the road from each other. Were not telling any of them (they always go to the same hotel, same time of year etc so no need to worry there!) I was thinkin about an unofficial vow renewal...just us family and a short service with my partner saying a few words. I've contacted the registrar to see if I can locate their original vows to re-do. Whats your thoughts? Good, bad or indifferent? I want to make it an even more special ocassion and print out a wee unofficial certificate to complete it. I was thinking, bouquets, just holiday dresses (everyone goes a little fancier when theyre going for dinner anyway right?), lots of photos, even a small scale wedding cake to take to dinner for after the meal. Help! Xxx”