Restaurants are typically experienced in social contexts along with companions. It has been found that these companions determine how customers react to service. This research aimed to how group size and tie strength influence customer dissatisfaction evaluation toward a service firm after suffering from other customer behavior. Questionnaire was used to collect data from 190 participants randomly chosen from restaurants in Alex. The results revealed 94.74% of the sample was bothered by obtrusive customer. Also, results demonstrated that group size significantly affected participants' dissatisfaction evaluations. In addition, participants in weak tie condition scored higher levels of dissatisfaction when the group size was small than when it was large. Therefore. Restaurants policies should consider seating patrons in a separate area where they would be less disturbed by the potential misbehavior by well-designed reservation system and employee training.