Communication technology enables employees to be constantly connected at the cost of potentially blurring the boundaries between work and private life, which can be detrimental to their well-being. The present study utilised a quantitative diary approach (
N
= 269 employees,
N
= 1256 data points) to provide further evidence on the association between telepressure and ruminative thoughts within boundary-crossing contexts (i.e., including work-related behaviour and cognitions during leisure time as well as private-related behaviour and cognitions at work). On a day-to-day level, we examined if context-incongruent telepressure had a positive effect on context-incongruent affective rumination through context-incongruent message-based communication behaviour. Multilevel analyses supported our hypothesised mediation models. Altogether, findings reveal that quickly replying towards messages or its related cognition (i.e., telepressure) may result in a resource-draining experience in terms of affective rumination within both boundary-crossing contexts. Theoretical and practical implications as well as future research avenues are discussed.