I designed an experiment,in which there is one two-level categorical independent variable, and a continuous variable as a covariate. The interaction between the two is not significant, however, when I look at the correlation between covariate and dependent variable at each level of the categorical independent variable. The correlation is significant at one level, but not the other. This pattern shows up repeatedly when I use multiple experimental stimuli, and is consistent with my theory. So can I still interpret the result, even if the interaction effect itself is not significant?