Do you think this is a little tacky? Or nice?

[briggsy's girl]

Do what feels right for YOU!

the ONLY downfall to a surprise wedding at your 21st is that some people may decide it's just a birthday, it's for a younger person, they won't come (esp the older generation), whereas they would come to a wedding. so you're left with people missing that might have otherwise been there for your big day... but ultimately it's about you and DP, so you need to decide whether you're happy to have some of those people missing kwim?

[Pretty Butterfly]

I think its a gorgeous idea, but agree with what BG said.
My cousin did the exact same thing earlier this year, and a lot of people didnt go, thinking they'll head up to see them at the wedding!!!
As most had to travel, a lot of people missed it by saying no and not attending her "birthday".

[Arimeh]

Works for famous people - and you guys are gorgeous just like famous people - so why not!!

[Mollie89]

A friend of ours did something similar, said they were having an engagement party that was themed, and everyone had to dress up a certain way..
then...

BAM out walks a celerant and they got married in a lovely garden..

I think if you like the idea, then you should defs go ahead with it!!

[Pretty Butterfly]

If you dont have to worry about people not coming, go for it babe!!

It takes out SO much of the cost, and hassle, and will prob be much more enjoyable for you both!!!!!

[blessedatlast]

I think it's a nice idea And hopefully DF wont forget the anniversary if it's on your b'day lol

[suse]

Friends of mine did this, it was supposed to be a 40th birthday, but the big surprise was that the bride didn't know about it beforehand either Seriously, I'd marry a guy who went to all the trouble of organising a surprise anything, let alone a wedding.

I think it sounds lovely!