Young men who have sex with men are at high risk for HIV, and most new HIV infections occur in serious relationships. This pilot study assessed the feasibility, acceptability and preliminary efficacy of the 2GETHER couples-based HIV prevention and relationship education intervention for young same-sex male couples. We enrolled 57 young male couples (N = 114) into a four-session hybrid group and individual intervention. We assessed acceptability via post-session surveys and exit interviews, and we examined preliminary efficacy at a two week posttest. The vast majority of participants (93%) reported exclusively positive impressions of 2GETHER, and all components received high mean ratings. We observed decreases in HIV risk behavior, increases in information, motivation and behavioral skills related to HIV prevention, and improvement in relationship investment between pretest and posttest. Integrating relationship education and sexual health programming may be an effective way to reduce HIV transmissions in young male couples.