Consumers¡¦ misbehaviors are common in service settings today. Therefore, the traditional idea of ¡§customers first¡¨ should be challenged. Besides, the scholars are paying more and more attention on the problems and effects comes from ¡§Jaycustomers¡¨. However, there was lack of discussion on ¡§Jaycustomer behaviors¡¨ through experimental research. As a result, this research focuses on Jaycustomer¡¦s characteristics, which including the perceived severity and size, and focuses on service provider¡¦s intervention behavior. And the research purpose is finding out that if the perceived severity of Jaycustomer behaviors and the Jaycustomer¡¦s size have effects on other customers¡¦ emotional state. Furthermore, this research also aims to understand the influence of service provider¡¦s intervention to customers¡¦ emotions, satisfaction, and WOM. This research reports an experimental design in the context of coffee shop with eight (2¡Ñ2¡Ñ2) scenarios. Two hundred and nineteen questionnaires were gathered. According to the gathered data, the conclusions of this research are summarized as following: 1. Different Jaycutomer behaviors will make people have different perceived severities. And higher perceived severity of Jaycustomer behaviors makes lower degree of customers¡¦ positive emotions and higher degree of negative emotions. 2. When Jaycustomer¡¦s size is getting higher, other customers will have more negative emotions. 3. Customers being in the same service settings or having eye contact with Jaycustomers, even without physical contact, will still be affected by them. 4. Service provider¡¦s intervention will raise other customers¡¦ positive emotions and lower their negative emotions. Consumers¡¦ positive emotions with intervention will be higher than the positive emotions with no intervention. And consumers¡¦ negative emotions will be lower than the negative emotions without intervention. 5. When consumers have higher positive emotions or lower negative emotions, they will more satisfy with the service, and they will have more positive WOM behaviors.