I don't know about signing blood contracts, but they get on because they all party with each other. They do hard drugs, and that lowers your dopamine, so naturally if they have money to get high all the time, the next thing to come is freaking off more then they used to.
I know they all fukk around, its a creative industry, and creative people like sex, and the women can do it without feeling like hoes, like square women do. What makes them get into same sex shyt, is the drugs(if they weren't born that way), I seen it with my own eyes. Once I started learning how the brain works, it all started making sense. Heavy alcohol use does the same thing. All you need is the right environment to bring it out the freak in you.