This phrase is used to describe something that won't last long, similar to how a meringue wouldn't last long in front of a school as it would be eaten quickly by children.
Examples
- Spanish: Esa camiseta te va a durar como merengue en la puerta de una escuela, es de mala calidad.
- English: That shirt will last as long as a meringue at the door of a school, it is of poor quality.