In one county of Southwest China bordering Myanmar, large numbers of minority Dai women leave to work in southern Thailand. Many are married and they leave behind husbands and children, sending remittances and returning home intermittently. These women commonly establish relations with Chinese/Malaysian men in their worksites - massage parlours in the tourist sites near the Malaysian border. These men become second husbands just as the Dai women become second wives. This paper examines the complicated set of HIV risks and assumptions that emerge from the circular Dai exodus to Thailand and the manner in which transnational employment networks impact on domestic and sexual relationships for women and their non-migrant husbands back home.