The phrase "brief encounter" refers to a short and temporary meeting or interaction between two people. It suggests that the interaction was not prolonged or will not have a lasting impact. Full definition
In addition, this information is readily accessible during brief encounters with the mother and child, and is often part of routine assessment. (academic.oup.com)
I'd explain who they are, but as quick as I do, it would spoil what they do as they all are only on the screen for very brief encounters. (fatmovieguy.com)
Furthermore, there are also growing number of online hookup site, where brief encounters can be made easy and fun. (articlesfactory.com)