This research study examines the association between psychological entitlement and employee negative behavioral outcomes i.e. knowledge hiding behavior and instigated incivility accompanied by mediating role of abusive supervision perceptions. Furthermore, the intervening effect of job stress between psychological entitlement and instigated incivility is also analyzed. Apart from testing these underlying mechanisms, this study elaborates the moderating impact of hostile attribution bias on the association between psychological entitlement and abusive supervision perceptions. The buffering influence of rumination on the linkage between abusive supervision perceptions and two behavioral outcomes i.e. knowledge hiding behavior and instigated incivility is also analyzed. In addition, this research highlights that whether the sense of job calling moderates the positive impact of job stress on instigated incivility or not. Current study follows a sequential explanatory mixed method design where the first phase is quantitative in nature and the second phase is qualitative. In the quantitative phase of the study, data were gathered from 513 respondents in three time lags. Moreover, stratified random sampling technique was used for the stratification of the service sector followed by convenient sampling for data collection from the sample. In order to further explain and validate the quantitative results, unstructured one to one interviews from eight participants using the maximum variation sampling technique were conducted. Ten themes with corresponding subthemes were emerged in the qualitative phase. Integrated analysis of both phases was conducted at the end in the form of elaborate discussion. The quantitative results revealed that psychological entitlement is positively and significantly associated with knowledge hiding behavior and instigated incivility of employees. Furthermore, the mediating impact of abusive supervision perceptions and job stress were found significant. Moreover, the moderating impact of hostile attribution bias and job calling were also proved. However, the boundary level effect of rumination on the association between abusive supervision perceptions and knowledge hiding behavior and between abusive supervision perceptions and instigated incivility was found insignificant. The results of all the hypothesized relationships were further elaborated in the light of qualitative findings. The themes generated as a result of thematic analysis explained significant and insignificant findings of the quantitative phase. This research study also unfolded certain theoretical implications, practical implications and future research directions.