Blackboards in Porn

"Celebrating pornographers who go the extra mile when set dressing classroom porn and actually write something on the blackboard. What do they write, and is it correct?"

http://blackboardsinporn.blogspot.com/

Also as a side note... my wife found this site. But what's crazy is my wife is terrible at using the internet. In fact she is just terrible at using computers in general. So, she was EXTREMELY excited when she showed me this. It's even stranger that she found it first because it involves porn.