strictly speaking scientifically, condoms only protect you from a handful of STD/STI's. Everything else can be contracted easily even with the safest of methods. Hence why half the world population, and 2/3's of the US population is estimated to have HSV-1. Clap and Chlamydia can be spread with oral, and syphilis can spread to anywhere that's not covered.
Add to that, the girls I've been with get tested regularly, LSC Tera showed me hers which is how I found out her real name