But on more than one occasion these private tapes have been made public -- from Paris Hilton's infamous sex-tape scandal to the latest footage faux past: reputedly "raunchy" tapes made by celebrity ex's Kate Moss and Pete Doherty.
Supermodel Moss is reportedly trying to prevent ex-boyfriend Doherty from releasing personal video tapes they filmed together before they broke up this past summer, according to the New York Post.
The paper reported that Moss said she'd be "horrified" if the tapes were leaked to the press, and added that she always thought the "raunchy" footage would be kept private.
Moss follows a long line of homemade celebrity pornography, such as Colin Farrell, who sued ex-girlfriend and Playboy playmate Nicole Narain after she attempted to release a sex tape of the duo.
And it's hard to forget Paris Hilton, whose sex tape with ex-boyfriend Rick Salomon is believed to have catalyzed the heiress's present-day fame.
Despite such a likelihood that these private tapes will one day be made public -- be it by a disgruntled ex or a YouTube-happy friend -- both celebrity and noncelebrity couples still can't help themselves from pressing "record."
Couples Make Sex Tapes More Often Than You'd Think
"There are more people than you would imagine who live next door to you or down the block that have at least taken pictures of themselves having sex," said Judy Kuriansky, clinical psychologist and author of "An Idiot's Guide to a Healthy Relationship."
"It's more common than you think."
Making sex tapes isn't anything new, said Kuriansky, who said it's been going on for at least 20 years, and even before then couples would commonly send each other nude photos of themselves posing.
"It's fairly common, even if it's with your own little camera at home, [for couples to make sex tapes]," said relationship expert Bethany Marshall. "With YouTube and MySpace and the Internet in general, everyone thinks they can be famous for a day sex tapes fulfill that fantasy."
Attention is the primary reason more sex tapes are produced, several psychologists told ABC News. Everyone enjoys being in the spotlight and feeling special, even if it's only caught on their personal camcorder.
"Exhibitionism and voyeurism are components of the sexual drive," said Marshall, who added that couples are more likely to make these kinds of tapes early in their relationship. "At the beginning couples tend to experiment more -- they want to feel like rock stars and they want to feel special."
Is the Chance of Embarrassment Worth It?
While the sex tape of an average couple isn't likely to get plastered across the front pages of popular gossip magazines, celebrities who record their bedroom antics do run the risk of being exposed.
But stars aren't fazed by the prospect that their tapes will become public, said Geoffry White, a celebrity psychologist in Los Angeles who attributes this to a celebrity's feeling of invincibility.
"The more of a celebrity you are and the more your narcissism gets fulfilled then the more you start losing touch with reality in the sense of consequences," said White. "Reality slips away from them gradually and pretty soon they're doing things [without thinking]."
The most spoiled celebrities, said White, don't recognize the potential repercussions of making sex tapes because they know it will not be their job to clean up the "mess."
"Sex tapes are nothing to be ashamed of anymore; it won't damage your career and you can make money and get famous from it," said psychologist and sex expert Kuriansky. ""[Paris Hilton's] tape absolutely made her name and career.
"It becomes ho-hum after a while," said Kuriansky, who explained that sex tapes aren't as jaw-dropping as they used to be. "If anyone wants to jump on the bandwagon now, they better get on it quick before it gets old."