A one night stand is a sexual encounter that is both brief and casual in nature. Most commonly, this occurrence takes place at the end of a night out and with a stranger. Often the man and woman will meet each other in a bar or nightclub, and escalate things over time, resulting in sex. If this happens in the same night that you got to know her, it’s called a Same Night Lay (SNL).
It is generally accepted that a one night stand (in contrast to a SNL) is exactly that – a one time thing. It is quite common for the man and woman to not see each other again after the sexual encounter. As such, it is not necessary to build rapport and comfort with the girl to the same extent as it would be were the intention to see her again and again. That said, the girl does need to feel comfortable in the moment and there has to be a lot of attraction going on for things to end up back in the bedroom so soon.
It is, however, perfectly possible to turn a ONS into an ongoing relationship of some form. If there was a good, natural chemistry between the couple, they could start to see each other regularly for casual fun or even a monogamous long term relationship.