The 80's were a wierd era and there was a ton of date rape that happened at HS parties and get-together events such as yours.
Consent? There as no discussion or even inkling what that meant back then. I remember how senior boys would prey on freshman girls but getting them drunk at parties and then becoming bf/gf. We all thought that's how life was.
I'm so glad that nowadays consent is openly being discussed. I had this conversation with my teenagers recently and they understand that it's not only OK but important to ask someone "May I kiss you?"
Granted we still have a LONG way to go but there's hope that it's in the right direction.