This study explored ethnic identity and acculturation experiences of bilingual individuals of Chinese descent living in the United States, along with their engagement with English and Chinese languages in sexual and romantic relationships. Chinese bilingual young adults in the United States (n = 190) completed an online survey assessing acculturation levels and sexual attitudes and behaviors. After controlling for covariates and other acculturation factors, mainstream U.S. acculturation (−), bicultural identity conflict (+), and preference for heritage language (−) were all associated with sexual communication. Mainstream acculturation (+) and preference for heritage language (−) were associated with sexual assertiveness. Approximately half of the sample also provided open-ended descriptions of their use of Chinese and English, clarifying the ways they use different languages to accomplish different relationship goals. Language proficiency was the best predictor of language preference, regardless of the context or the topic of conversation. However, an association between language and cultural values was observed, such that participants tended to be more comfortable with English for sexual communication, stating that Chinese lacks sexual vocabulary. In addition, when expressing negative feelings, Chinese appeared to convey more intense emotion than English for many participants. The current study has implications for culturally adapting sexuality education for Chinese bilinguals in the United States.