This article explores polyamorous men’s potential to both enlarge and reinforce the concept of hegemonic masculinity through their emotional expressions and management, as well as their sexual expressions and relationships. Polyamorous people openly engage in romantic, sexual, and/or affective relationships with multiple people simultaneously. Polyamory differs from swinging with its emphasis on long-term, emotionally intimate relationships; and from adultery with its focus on honesty and (ideally) full disclosure of the network of sexual relationships to all who participate in or are affected by them. Both men and women have access to additional partners in polyamorous relationships, distinguishing them from polygynous ones. My ethnographic analysis expands sociological understandings of hegemonic masculinity by investigating this previously unexamined area of men’s sexual and romantic interactions. Employing R.W. Connell’s framework of hegemonic masculinity, I analyze some of the ways in which the polyamorous men in my sample are complicit with, marginalized by, subordinate to, and resistant of hegemonic codes of masculinity. I thus expand Connell’s configuration of hegemonic masculinity to include active defiance to its requirements and conclude that, to varied degrees, these poly men attempt to redefine their masculinities and resist the strictures of hegemonic masculinity.