I never said that.
All I said was the reason sex exist is to reproduce.
Fun is a byproduct, therefore the secondary purpose.
Now most people do have sex more for fun than reproduction. I never denied that or said it shouldn't be so.
But it does not negate the biological fact that sex is for reproduction, not fun.
Actually, the reason we do it is because it is fun. The reason it is fun is because being fun makes it more likely we will reproduce.
But we now have the technology to have the fun without having the reproduction. That means that fun is now more likely to be the reason people have sex. It was always one of the primary reasons.
And, of course, we also have other means of reproduction. So that can happen without sex.