This research attempted to investigate whether we can attribute unfaithfulness on the basis of facial expressions of emotion. Male and female subjects aged 19 to 89 participated in the study. The subjects evaluated images of male and female models that featured facial expression of anger, joy, disgust, surprise, fear, and sadness. The results indicated that male models were perceived with greater intentions towards infidelity than female models. Models expressing the emotion of fear and surprise were estimated more likely to be unfaithful, while those who expressed the emotion of sadness were significantly less prone to unfaithfulness. Estimation of intentions towards infidelity for women who express fear and surprise is significantly higher compared to estimates of female models under all other conditions. When men expressed fear, they were estimated with significantly higher intention towards infidelity than expressing any other emotional expression, while men who express sadness were estimated with significantly lower intention towards infidelity compared to an estimation of other male expressions. Age is positively correlated with self-assessment of intentions towards infidelity only in women. The female self-assessment of infidelity is not correlated with model's estimations of infidelity. The male's self-assessment of infidelity is positively correlated with estimation of the infidelity of female models who express sadness and surprise and male models with facial expressions of emotions of anger, disgust, surprise, happiness, and sadness.