The wedding sene?

It's called consummation. Here is the definition:
http://www.ask.com/web?q=dictionary%3A+consummate&content=ahdict%7C16112&o=10181&l=dir

And here is an article about it on wikipedia:
http://en.wikipedia.org/wiki/Consummation

Basically a marriage was not usually seen as binding until the first act of intercourse was performed between husband and wife. All the people around them sprinkling water were praying and giving them blessings for a fruitful marriage and to bear children.

This is also why some religions don't believe in contraception, because using it during intercourse goes against the church's law to bear children once married. And it also explains why some religions don't believe in sex before marriage because the act is considered a sacred unity of two people sharing and starting their life together.

I hope that helps!

"You can food anything if you just eat it." ~ Bucky Katt