It also has a horrifying history behind it.
Carrying a bride across a threshold into a room after the wedding ceremony is a traditionthat's going out of style, but it's been seen in dozens of romantic comedies and dates back thousands of years.
The tradition, according to the academic encyclopedia "Marriage Customs of the World," dates back to the The Rape of the Sabine Women, an event in Roman mythology where Roman soldiers abducted and raped the women in the surrounding regions. The women were carried off against their will.
Bizarrely, the event turned into a common Roman wedding practice. The bride, according to the encyclopedia, would run off to her mother while the bridegroom and his friends would intercept her and pull her away. And a group of people, not just the groom, would carry the bride into the house.
The most direct interpretation of the tradition is that it's a benign recollection of "marriage by capture." But the encyclopedia also offers a more charitable interpretation: that the wife wants to make a show about how she isn't eager to leave her parents' home and start a family of her own.
At some point, the threshold itself acquired its own meaning. In Britain, at least, it was feared that the threshold might contain "sorcerous drugs" or other malevolent powers that could destroy a marriage or the wife's child-bearing ability. For that reason, the groom tried to make sure that the bride didn't touch the ground.
The renowned poet Ben Johnson immortalized this interpretation in his 1606 work "The Masque of Hymen," where the speaker asks the bride to "lift your golden feet/Above the threshold high,/With prosperous augury."
Doorjambs and thresholds also have significance in a few non-Western marriage traditions. In Zorastrianism — an ancient religion that dates to pre-Islamic Iran — the doorjambs are smeared in turmeric after a wedding. The groom has to pass through without touching the threshold, and his new mother-in-law marks his forehead with red pigment and throws rice at him, according to the encyclopedia.
Today, people don't necessarily believe that the act of carrying the bride across the threshold has any significant meaning. For most, it's just a fun thing to do.