@gyl Ever had a surgery? Then you are not as nature designed you. Do you complain? Probably not. Nature didn't design many of the objects nor the habits you have/use in your everyday life, but that is not a problem to you, is it?
One thing nature did do though was making humans and animals flexible and customizable. It made us able to feel love towards people of the same sex. Also, in nature there is no sexuality. We just know what we need to do in order to reproduce and what we can do in order to pleasure ourselves. Dolphins are known to have sex for pleasure. They even rape humans sometimes. Even men. And yes, we die in the process.