Discuss this oxymoron in the comments below.
An expert on amateurs?
especially when discussing about sex..
You can be an amateur expert, an amateur is not paid for whatever the subject is, a professional is paid and that is the only difference.
An amateur is nothing like the level of a pro, saying the only difference is that one gets paid and the other doesn't is wrong. Is semi pro also an oxymoron? or a non profit organisation? perhaps hack is better description for this definition.
oooh you dirty boy!