Hi HRE -- I don't want to go too far down this path, but I don't think we are talking about "date rape" here. I'm sure perceptions of rape have evolved since the 1970s, and maybe it would have been swept under the rug back then (actually it was at Wellesley), but I don't think the meaning of rape has changed since the 1970s (although further back in time and history, consensual relations between a black man and white woman was considered rape). Unless you were Mormon, this kind of "relation" between 30-year old coaches and 15 and 17 year old athletes surely wasn't acceptable -- was there another term? Here's a couple of Wikipedia quotes I found about what constitutes rape (today?) and some evolution since the 1970s:
"Rape is a type of sexual assault usually involving sexual intercourse or other forms of sexual penetration carried out against a person without their consent. The act may be carried out by physical force, coercion, abuse of authority, or against a person who is incapable of giving valid consent, such as one who is unconscious, incapacitated, has an intellectual disability, or is below the legal age of consent. The term rape is sometimes used interchangeably with the term sexual assault."
"Since the 1970s, many changes have occurred in the perception of sexual assault due in large part to the feminist movement and its public characterization of rape as a crime of power and control rather than purely of sex. In some countries the women's liberation movement of the 1970s created the first rape crisis centers. This movement was led by the National Organization for Women. One of the first two rape crisis centers, the D.C. Rape Crisis Center, opened in 1972. It was created to promote sensitivity and understanding of rape and its effects on the victim."
"In the 1980s, date or acquaintance rape first gained acknowledgment. Rape crisis centers were created to serve survivors of all forms of sexual violence during any phase of their healing process. Rape crisis centers and other community-based service providers continue to grow and serve their communities by providing direct services and prevention programming."