Sex on the wedding night is often more about obligation and expectation than desire, say experts and the newly married. With many couples sleeping and living together for years before they get hitched, the complexities of the extravaganza can get in the way. 

"You shouldn't expect your toes to curl," said Lori Seto of theknot.com, a wedding Web site where people trade their wedding night sex tales. "And if you do have sex, it's just a token gesture." 

Between 10 and 30 percent of newlyweds don't manage to have sex at all on the night of their nuptials, according to surveys by Bride, Glamour and K-Y Brand Liquid. Maybe magazines and lubricant manufacturers don't sound like the most credible sources, but apparently they're the people who care. 

The K-Y study found some unexpected demographic differences: younger couples were twice as likely to skip sex than those 45 and older; and 74 percent of Southerners had sex on their wedding night, compared to a mere 62 percent of people living in the West. 

 
'I would feel let down if we didn't have sex on our wedding night, no matter how draining the evening's been' — Katherine 
 

The sex might be lackluster, but many are gung-ho anyway. 

"I would feel let down if we didn't have sex on our wedding night, no matter how draining the evening's been," said Katherine, a 26-year-old accountant from Fort Lauderdale, Fla., who's getting married in November. "Even if you've been with the person before, but you don't want to let one of these big moments pass you by." 

Among those who do choose to, um, sit out the wedding night, 32 percent were too tired, 12 percent too intoxicated, 5 percent "had to catch an early flight" and 2 percent were "not prepared." What, did they not bring the goods? 

The significance of wedding night whoopie is clearly greater when the couples don't sleep together prior to their wedding nights, but the number of newlywed virgins is surprisingly low. Some 97 percent of couples in the Glamour survey were not virgins on their wedding night; Bride found that only 4 percent of women and 1 percent of men waited. 

 
'There is great pressure on the couple to not only have sex, but to have the ultimate mind-blowing incredible experience. In reality, it's maybe the most likely night to not have sex' — Dan Zevin 
 

And although romance is supposed to override fatigue, it's unrealistic to think that the long wedding day won't have an effect in the sack, said Dan Zevin, author of The Nearlywed Handbook: How to Survive the Happiest Day of Your Life

"There is great pressure on the couple to not only have sex, but to have the ultimate mind-blowing incredible experience," he said. "In reality, it's maybe the most likely night to not have sex." And as anyone who's been through it knows, "You've just spent the last six months having the protracted mental breakdown known as wedding planning." 

The anxieties of the wedding alone are enough pressure, said Seto, that "the anxiety of having sex for the first time must be extremely difficult." And it does happen — just not as often as it used to. 

So wedding night lust can still be momentous — even when the couple's already had loads of practice. 

"We've been living together for a year and half, and we've been [having sex] for years," one woman wrote on theknot.com's discussion board. "But that night it was slow and sweet and we both cried. The rest of the [honeymoon] was all great, surprising, hot sex, but that first night was the best." 

Your experience may not live up to expectations, but even if you barely have enough energy to brush your teeth, Zevin said, "It's good preparation for life as old married farts — life where sex is not always going to be a party."