Unless you get a sealed and signed stamp of approval from the couple that they're ok with you making their celebration of love about your own relationship, you better think twice before making any major life announcements on someone's wedding day. Weddings require a great deal of planning and financial stress, and nobody wants to drain their savings account on an open bar just so their uncle can hijack the family gathering and renew his vows with his fourth wife. Excited to tell the whole family that you're expecting a baby? Cool! A wedding is not the time, Aunt Liz.
While weddings are always intended to be an event that honors the love a couple shares, reality has taught us that they can sometimes bring out the worst qualities in people. Brides who were previously normal people can definitely lose themselves in the chaos of flower frenzy, theme colors, bridesmaid squabbles and finding the perfect centerpieces. Doing anything that would take the spotlight off of the couple is a universally agreed-upon selfish and disrespectful move.