Our lives are being transformed by innovative software applications with important social, environmental, and economic implications. Social sustainability must be considered by software engineers to address human physical, emotional and social needs. In order to investigate how users understand and perceive the social sustainability of context-aware software applications, that are built based on the HAPPYNESS framework, we investigate a set of social sustainability-quality requirements from an end-user perspective. The perceived importance of social acceptance and perceived success are also measured. In this paper, we present the experiment design and the main outcomes of our pilot study conducted with the MEGSUS workshop participants.