Years ago Hustler did one of those evolution charts but instead of apelike dude to modern man it was of pornwhores (Nina Hartley was the punchline btw). It'd be great to do one of what pws will do as work. You could start it with 'solo girl', 'girl-girl' etc. and then end it with 'fucking Ron Jeremy' and 'Double Anal Creampie' etc.....
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"I'll never forget the moment during the lovely Alyssa Allure's scene in 'American Bukkake' where the fellow got out of his wheel chair to ejaculate on her face. It was grotesque but had a certain frisson." -Sock