Can Mac computers get viruses through booting into Windows XP?

I know that Macs are supposedly virus-free, but I also know that many viruses, trojans and forms of spyware exist for windows. Now that intel Macs can boot Windows XP, are they prone to these viruses? If that is possible, would the viruses affect the computer only when running XP, or would OS X also be affected? This might be a very stupid question.

if you share directory with write access, your windows viruses will infect/affect the mac files too!

while running os x, you can’t spawn viruses, but you can copy them around!

if you run both… keep the windows out of the mac directories!

guy with wierd face does funny stuff and pulls faces lol