1. Slang term for a bisexual.
2. Term for anyone/anything mixing two extremes.
1. If you're bi, you like guys and girls, which basically shows "gay" and "straight". You're half, or "point-five" of each, therefore a point-fiver.
2. Someone who's sweet as anything, but has a bad reputation is a point-fiver because they're half bad, half good.