Not using protection is a matter of trust. I meen if you want to be real strict about it you dont even bother getting the big and most important test (HIV) until 6 months into the relationship (as it can be present in the system that long before being sufficiently accurately detectable).
So options are to use protection for the first 6 months of any new relationship, or to make an assessment of this person you love and what they're telling you and take the risk.
Life is full of risk, sex is just another one.
Anyway it's ok for you guys, roll on a condom and you're sorted and it's no big deal, but for me it's more complex - have you seen those oral defenders? *shudder* If you've got a dentist fantasy then they're great, otherwise it's like licking a baloon.