yeah, my best protection against STDs was careful screening of partners. And if i liked them enough and they'd got one, well i better have been ready for it.
now it's monogamy, but like from my understanding most are manageable. Hell, only one out of the grampolycule was HIV positive if i remember right (they've all been gone... shit. it's been too long I'ma go watch the Birdcage), and i'm pretty sure they weren't celibate. just careful.