One-night stands are not limited to encounters between strangers. When people who have a friendship or business relationship have a one-time sexual encounter, and subsequently resume their previous relationship, it is still considered a one-night stand.
More About One-Night Stand
One-night stands fall under the umbrella term casual sex although they are distinct in their one-time-only nature. One-night stands can be the cause of hurt feelings when one party intends for an encounter to be the beginning of something bigger while the other does not.