The issues of sexual harassment, assault, and rape have been much in the news recently. It should be obvious that there should clearly be mutual consent. But for many people, the issue of what constitutes consent seems to be a little unclear. This video tries to clarify the issue, using other everyday exchanges that have none of the tension of sexual interactions, to illustrate the point.
As a general rule though, if there is any ambiguity, any doubt whatsoever in your mind as to whether consent has been given, assume that it has not.