20 Things You Somehow Missed In Back To The Future Part 2
6. Lorraine's Breast Implants Were Foreshadowed
One of the low-key most horrifying aspects of Biff's dystopian 1985 is that he not only killed Marty's dad but forced his mother Lorraine (Lea Thompson) to marry him.
Beyond that, Lorraine is an alcoholic and Biff also made her get breast implants, hence Marty's surprised line upon meeting her - "You're so... big."
This was actually slyly foreshadowed earlier in the film. In Marty's home in 2015, the gigantic multi-channel video screen displays an ad for two types of futuristic breast implants: inflatable and headlights.
Also, when Marty and Doc first arrive in 2015, we can see stacks of unused silicone material piled up by the wall, indicating that implants in the future moved away from that outdated design.