Using a newspaper questionnaire, a door-to-door survey, and 3 laboratory experiments, the authors examined a proposed effect of shared participation in novel and arousing activities on experienced relationship quality. The questionnaire and survey studies found predicted correlations of reported shared" exciting" activities and relationship satisfaction plus their predicted mediation by relationship boredom. In all 3 experiments, the authors found predicted greater increases in experienced relationship quality from before to after participating together in a 7-min novel and arousing (vs. a more mundane) task. Comparison with a no-activity control showed the effect was due to the novel-arousing task. The same effect was found on ratings of videotaped discussions before and after the experimental task. Finally, all results remained after controlling for relationship social desirability. Results bear on general issues of boredom and excitement in relationships and the role of such processes in understanding the typical early decline of relationship quality after the honeymoon period.(PsycINFO Database Record (c) 2016 APA, all rights reserved)