To be honest with you, I think you're choosing the wrong type of men to give you an orgasm. They need to know what makes a woman tick and cum. Now my husband can make me cum and squirt so hard it's unbelievable. When I fuck a black cock I also cum and enjoy it thoroughly. It's also addicting, the difference in the skin color, being watched, and also being naughty. It all plays a part. However, I dont think it matters who fucks you it's how they fuck you and if they know what they're doing. Good luck on getting your orgasm!