Corsages with magnets can fall off your suit at:
The Greeting Hug: Enthusiastic friends and family members can give you corsage pry loose in their attempt to hug you tightly.
The Festive Dance: Intense dance moves, especially at the opening dance, can cause you to corsage releases.
Posing for Pictures: During the photo shoot at the dip, for example, or because you are going against each other.
Top-heavy Corsage: If you corsage is particularly large or heavy, gravity can cause it to tilt and eventually fall.
The Gust of Wind: An unexpected gust of wind, for example when riding in a convertible or standing in a windy location, can make your corsage tear loose.
The Waving Moment: When you wave to the crowd or just gesture during a conversation, the quick movement can make you corsage loosening.