This study explores how social media constructs sexual deviance and violence against women. Based on vigorous debates on Facebook about the cheating of case two Hong Kong celebrities, we analyzed how cheating and promiscuity are constructed as sexual deviance on social media in Hong Kong through a politics of claims-making. Research has demonstrated how promiscuity and cheating are facilitated through the Internet. It has yet to show how social media sustains compulsory monogamy and constructs promiscuity and cheating as deviance to induce violence against women. Our study contributes to understanding how CM is sustained and how it constructs sexual deviance in scoial media. We discovered that discussing taboo sexual practices through Facebook involves mainly punitive informal social control and only strengthens the stigmatization of them, regulating gender and sexual morality, sustaining compulsory monogamy, and oppressing women and practitioners of marginalized sexual behaviors. We call for updated measures on social media outlets like Facebook to regulate cyber violence and encourage civilized discussions on taboo sexual topics.