Young men are more distressed by a partner’s sexual infidelity, whereas young women are more distressed by a partner’s emotional infidelity. The present research investigated (a) whether the sex difference in jealousy replicates in an older sample, and (b) whether younger people differ from older people in their selection of the more distressing infidelity scenario. We presented forced-choice dilemmas to 202 older people (mean age = 67 years) and to 234 younger people (mean age = 20 years). The sex difference (...) replicated in the older sample. In addition, older women were less likely than younger women to select a partner’s emotional infidelity as more distressing than a partner’s sexual infidelity. Discussion offers directions for future work on sex differences and age differences in jealousy. (shrink)