Obviously between two biological females the possibility of pregnancy is 0% however in terms of STD's how do lesbian and bi girls protect themselves other than getting tested?
Most simply don't. Have you heard of 'dental dams'? They're 'condoms' for oral sex but are rarely used.
Yeah, dental dams were designed for oral sex, and gloves can be used when fingering. Condoms when sharing toys, as well. But like blueberrykisses said... Safe sex is not really a huge concern for many WSW. I'm not saying it's a good thing -- that's just the way it is. Oral and fingering a woman are not hugely high-risk activities, and many women seem to think they're not at risk just because they're having sex with another woman. Even though we can still get STIs...
STDs should be a concern for lesbians because the ones who think they have nothing to worry about will most likely get one. Hahah I ended up being that kind of grrrrrl. Latex gloves are great, you can get a box of 100 for pretty cheap. You can buy dental dams online usually however they are pricey, so you can cut a condom into a square sheet. I have been to several events that give away free condoms so it doesn't cost you a dime. Check this website out www.sexualityandu.ca/ Always bring up STD status when having sex with someone, even if you don't have one. Always protect yourself and your partner. Use water-based lubricants to prevent any tearing, and for comfort. Check out the website I sent you. It's pretty inclusive and gives you a lot of info.