http://en.wikipedia.org/wiki/One-night_stand
A one-night stand is originally a single night theatre performance (usually a guest group on tour), and today more commonly also a single sexual encounter between individuals, where neither individual has any immediate intention or expectation of establishing a longer-term sexual or romantic relationship.
The individuals participating in a one-night stand typically have not known each other long and have had minimal time to get to know each other before engaging in sexual activity. A one-night sexual encounter is not necessarily always a one-night stand; the crucial distinction is the expectation or intention that the relationship will not necessarily be extended beyond the initial sexual encounter. A one-night stand is differentiated from prostitution, as it takes place without direct payment of money and from a casual relationship, which may not initially involve sex and may continue long-term. The term came from the expression one night stand, used for a touring theatrical company who would make a single performance in one locale before moving on to the next engagement, and to a place where such a performance was given.
During sex females get such a strong dose of oxytocin that "when women think they can have sex and walk away just like guys do, they’re having to suppress thousands of years of evolution that tells them to cuddle, stay in bed, and look forward to tomorrow. When they get up and walk out, they feel depressed and don’t know why."Researchers have found that women’s feelings after one night stands are much more negative than men’s. Feeling ‘used’ was the predominent negative emotion they felt the next morning and they also worried about their reputations and felt as if they had let themselves down. Professor Anne Campbell from Durham University said "What the women seemed to object to was not the briefness of the encounter but the fact that the man did not seem to appreciate her. The women thought this lack of gratitude implied that she did this with anybody."
A one-night stand can be thought of as an irregular and unplanned sexual encounter between individuals. The participants will usually have little or no contact with one another aside from sex. Thus it is possible to have multiple one-night stands with the same person, provided that there is no regularity to the encounters or planning involved in the encounters. However, where the people involved have a regular sexual relationship without romantic involvement, this is generally considered a casual relationship (also referred to using terms such as "no strings attached"/NSA, "fuck buddies", or "friends with benefits"/FWB), and is generally considered distinct from the one-night stand phenomenon.
The risks of participating in one-night stands can include the risks of having unprotected sex, such as unwanted pregnancy or contraction of STDs. Effective use of contraceptive devices can help combat STDs.
My Thoughts
Ok, I found the definition of ONS at WiKi. Good. Be specific … I never condone prostitutions. And WiKi defined that as NOT ONS as ONS does NOT involve money(free-sex?). You might pay the lady for a drink/dinner … but not for sex favour. ONS is NOT sort of planned(it can be planned prior to the meeting, i think) as it is NOT on regular basis. In fact, from what i could understand, it is a ONE-TIME go such of things. No string attached. Mutual. No force or even persuading. But, according to WiKi, as long as it is irregular, we could have the SAME sex partner(s) and that is still defined under ONS.
You see, sometimes u do like the partner(physical side, no emotions entanglements, please) and you might end-up being a casual friend. Unless it is REGULAR(termed as Casual Relationship?), it is ONS. That is! I got it WRONGly defined all this while! Haha.
How about staying with an opposite in same bed WITHOUT sex? Yeah right, you mean they are NOT aroused or so well disciplined? It is surely possible. Is such encounter defined as ONS? He/she can be your bed-partner … but never engaged in sex?(no penetration and such, perhaps confined to hugging/kissing).
How about this … you are staying with a person(we assume that you are straight and the person is of opposite sex) for a week, have sex included, but never see him/her anymore there after? No contacts and such? Is that casual relationship or ONS or neither? Hmm …
