If anybody forces anybody to do anything sexual that they don't want to do, then it's wrong.
It doesn't matter if you're four, fourteen, or forty. Obviously the forty-year-old has a better chance of fighting off an attacker than the four-year-old, but it's still molestation. It's still rape.
The second that someone says "No, I don't want to do this" and someone keeps going, it becomes something that is illegal.
No exceptions.