A Jewish wedding ceremony, like many other religious rites and ceremonies, is governed by many laws and customs. One such instance is the period of yichud -- seclusion -- that the bride and groom spend together right after the chuppah.
It should be pointed out, however, that this is *only* the case for Ashkenazim. When a Sefardi couple gets married, they do not go to the yichud room. For them, yichud is performed when the couple goes home after the ceremony. In fact, Rav Yitzchock Yosef considers the idea of a yichud room during the wedding so repugnant that he called it "ugly" and "vulgar." I don't think it's proper for a Rav to call a mainstream Ashkenazi minhag "ugly" and "vulgar" I made my point on that in the linked post)-- but that's really beside the point. The main point for our purposes is that there are strong opposition in at least some Sephardi circles against the practice of going into the yichud room.
With this background information, we can look at a recent event. Rafi, over at Life In Israel, reports on a recent wedding where a Sephardi couple was married. The chosson attended an Ashkenazi yeshiva and his Rosh Yeshiva and friends from the Yeshiva were in attendance. The Rosh Yeshiva directed that the chosson and kallah should go immediately after chuppah to the yichud room, in accordance with the Ashkenazic custom. The chosson refused, intending to follow the custom of his family and the new bride's family. When the chosson refused, the Rosh Yeshiva announced that he was leaving and ordered all the bochrim from the yeshiva to leave with him. Fortunately, Rav Raphael Cohen, a guest at the wedding knew someone at a local Sephardi yeshiva, where they had the boys stop learning and go be mesameach (make merry with dancing) the chosson and kallah.
To me, there are some very troubling aspects to this story:
1. Since when does the minhag of the yeshiva overrule the family minhag of the bride and groom? Do they also expect their Sephardi students to refrain from eating kitniyos on Pesach in their homes? Would they say that it's all right for an Ashkenzi student attending a Sephardi yeshiva to skip the yichud room? I don't think so. Minhagim have long been observed on the basis of inheriting them from your family, not on the basis of what yeshiva you attend. Perhaps there is some basis after all to the fear that some Sephardim in Israel have that their minhagim and other cultural attributes are being slowly eroded by the Ashkenazim.
2. Ultimately, a wedding is valid, even according to Ashkenazim, if the chosson and kallah never go into the yichud room during the wedding. As long as there are witnesses that they went home together (and were alone together) after the wedding, the wedding would be 100% valid. On the other hand, embarrassing the bride, groom and their families is a transgression of a Torah prohibition. How could the Rosh Yeshiva possibly think that his custom (or the custom of his yeshiva, if you will) possibly overrides that?
UPDATE (3/17/11): A commentator has offered an alternate version of the events. I have no way of knowing which is true or not, so take your pick.