Oral Issues

I would like to ask Teak and others why are you so sure that giving oral sex to a man in the presence of precum but in the absence of semen is risk free? I am curious and would like to understand how it is. Could you please explain it for me?
Thanks.

[Teak]

Oral transmission of HIV, reality or fiction? An update
J Campo1, MA Perea1, J del Romero2, J Cano1, V Hernando2, A Bascones1
Oral Diseases (2006) 12, 219–228

AIDS:  Volume 16(17)  22 November 2002  pp 2350-2352
Risk of HIV infection attributable to oral sex among men who have sex with men and in the population of men who have sex with men

Page-Shafer, Kimberlya,b; Shiboski, Caroline Hb; Osmond, Dennis Hc; Dilley, Jamesd; McFarland, Willie; Shiboski, Steve Cc; Klausner, Jeffrey De; Balls, Joycea; Greenspan, Deborahb; Greenspan, John Sb


Shugars DC, Sweet SP, Malamud D, Kazmi S, Page-Shafer K, Challacombe SJ (2002)
Saliva and inhibition of HIV-1 infection: molecular mechanisms.Oral Diseases 8: 169-175 Suppl. 2 2002

Study Shows Component of Saliva is Very Effective in Blocking AIDS Virus Potential for Use in Preventing Sexual Transmission of HIV
http://www.aegis.com/news/pr/1998/pr980105.html

Study: Saliva Prevents AIDS
http://www.aegis.com/news/ap/1995/ap950114.html