Hello, Jamie!
Welcome to the Disney Parks Moms Panel. Thank you for sending us your question and I hope that you will continue to visit the Moms Panel if you have any more questions before traveling to Walt Disney World Resort! Your vacation is almost here, how exciting!
Nothing will happen if one of the adults in your party decides to not use his/her
FastPass+ selection at the last minute. The FastPass+ selection will “time out” but it will not affect his/her other FastPass+ selections or the selections of anyone else in your party.
Mom's Quick Tip: To make your FastPass+ group selections easier to manage, change or share I highly suggest adding your travel mates to your My Disney Experience account's Family & Friends list and downloading the
My Disney Experience mobile app.
Jamie, if you have any more questions about FastPass+ planning or need help planning your Walt Disney World Resort vacation please visit me on the Disney Parks Moms Panel again!
Wishing You an Unforgettable Vacation,
Priscila