Service excellence principally depends on the critical interactions that take place between the front line employees (FLE) and the customers. Front line employees experience job strain because of their boundary-spanning roles trapped between the expectations of the organisation and the expectations of the customers. There is a scarcity of literature on the individual coping tactics employed to ease strain. Our study focuses on this research gap by exploring pro-socially motivated rule breaking behaviour of FLEs. When confronted with conflicting expectations, employees may decide to act in the overall interests of the organisation or its stakeholders by even overriding the established routines, rules and regulations. The purpose of the present study is to empirically test a theoretical model using pro-social rule breaking behaviours as employee coping and how different pro-social rule breaking behaviours such as job oriented, co-worker oriented and customer oriented influence Leader-member exchange and job strain relationship. Drawing from the job demands-resources model, this study hypothesizes that some pro-social rule breaking behaviours moderates leader-member exchange influence on job strain relationship. To test these hypotheses, the study administers a survey among 234 frontline employees of a state public utility organisation in India. Model building is undertaken using hierarchical multiple regression and process macro. The results reveal that the impact of low quality leader-member exchanges on job strain is minimized when frontline employees engage in customer oriented rule breaking while only at low levels job oriented rule breaking strengthens the negative effect of leader member exchange on job strain. But coworker oriented pro-social rule breaking behaviours has no significant effect on the relationship between leader-member exchange and job strain. This research contributes to the constructive deviance and frontline employee literature by establishing the role of customer oriented and job efficiency oriented pro-social rule breaking behaviours as job resources or job demands. The role of supervisors in managing work place job strain and employees response to the relationship will be under the scanner.