Aspects of the Jewish wedding: the conclusion of chuppah - yichud

After all the blessings are recited, and the bride and groom have sipped from the cup of wine, a glass is broken to remind us that we are not completely joyful in while our Temple remains in a state of churban [destruction]. As people have become accustomed to taking the sound of stomping on the glass to signal the culmination of the wedding ceremony, they usually shout out “Mazel tov!” right after hearing it. Consequently, some people have taken to singing “Im eshkachech Yerushalayim tishkach yemini” [If I forget you, Jerusalem, let my right hand be forgotten (from Tehillim [Psalms] 137) to remind the assembled of what the broken glass is intended to signify. Some frown on the addition to the traditional ceremony and so will refrain from singing. In any case, it is proper to pause between the sound of the breaking glass and the shouts of congratulations to mark that one is a memorial and the other a celebration.   See Why-we-break-a-glass-at-Jewish-weddings

The Ashkenazic custom is for the couple to enter into a private room by themselves for yichud [seclusion] right after the chuppah. It is not merely to give them a few (usually 10 -15) quiet minutes together and to break their fast before joining their guests. The seclusion of the couple is necessary to complete chuppah, and, according to some views, is even the definition of chuppah. Prior to marriage, a single man and woman avoid situations of intimacy in which they will be closeted together out of view of anyone else. So their seclusion for a time period that would suffice for intimacy is a sign of their married state. Some people even designate witnesses for this step; they make sure the room is free of all other occupants before the bride and groom enter.

While the yichud part of the wedding is a very special time for the bride and groom, they are usually summoned out all-too-soon for their liking. That is because the photographers want them present for pictures, and they also have to bear in mind that their guests await their return to the hall to begin dancing in front of them in fulfillment of the mitzvah of being mesameach chasson vekallah, [gladdening the groom and bride].

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