As one of the unfortunate few who make the difference between no-risk and low-risk I can attest to the fact that pre-cum can--and did, in my case--make you seroconvert. Since 1981 I had safe sex, within monogamous relationship. In 1996 I sucked ONE cock, in July, without a rubber, for about one minute, no cum. That was the only sex I had. Two weeks later I had, according to my then doctor, a probably viral infection of unknown causes (flu-like, with spots all over my body). 6 months later, tested positive during routine physical. Low risk doesn't equal no risk.