Consensual nonmonogamy is a term used to describe intimate romantic relationships that are sexually and/or emotionally nonexclusive. The present study examined the social norms that are violated by different forms of consensual nonmonogamy and the negative judgments that result. We asked 375 participants to rate hypothetical vignettes of people involved in one of five relationship types (monogamy, polyamory, open relationship, swinging, and cheating) on items related to relationship satisfaction, morality, and cognitive abilities. The monogamous couple was perceived most favorably, followed by the polyamorous couple, then the open and swinging couples who were rated equally. Participants judged the cheating couple most negatively. Although social norms of sexual and emotional monogamy are important, we conclude that the aspect that has the most effect on judgments is whether the relationship structure has been agreed to by all parties.