sam2: see, also Yoreh De’ah 114:1. Sepharadi Jews who do not hold by the leniency of the Rama there indeed hold like the Rambam as hershi states prohibiting all drinking at bars/clubs and non-jewish parties. See, also, the Beis Yosef on Yoreh De’ah 112 which proves the Rambam from the gemuruh in avoyda zuruh daf lamed umud alef.
you can do what you please but i believe hershi’s logic is spot on and that it is indeed ussur to drink at bars/clubs/goyesh parties.