This focus that society has on natural vs. unnatural is bizarre to me. It's unnatural to fly on an airplane. Doesn't mean it's bad. Things need to be proven on their own merit whether they are bad or good not just because something hasn't been done before.
The age difference one is more annoying because it doesn't even many times have anything to with pedophilia. Had so many people telling me this 19 year old I was dating last year was too young for me. If only they knew.