Just propose. On a plane if necessary. Please leave everyone else out of it.
Sorry to sound harsh, but I have NO interest in being forcibly made to listen such things....
Yes, it's HUGE for them, and congratulations, best wishes etc... but I'm sorry. I DON'T care, and would thank other people not to (selfishly?) want to disturb a planeload of strangers with their private business.
Apparently there is an average of 6,200 weddings a DAY in the USA.....
Good evidence indeed that while it is special to the individuals concerned, it is far from a unique event.