ELI5 Weddings - why shouldn't the groom see the dress beforehand?

Why is there the tradition of not seeing the bride in the wedding dress beforehand? Where did something old, something new, something borrowed and something blue come from? Why is there a tradition of smashing a glass at the end of Jewish weddings? What happens if someone 'objects' during the ceremony?   ... We explain like i'm five!   Thank you to the r/explainlikeimfive community, and specifically the following reddit users whose questions and responses formed the basis of this conversation: londonpilot, ayrilios, drocd, redditedself, me_suds, memehehe & yorkshire45   To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Send us an e-mail: [email protected]