What's the risk of contracting an STI or STD?

[K. in Cleveland]

Logic cannot tell you your both clear if you haven't been tested! Like I said, most of these nasty bugs can lie dormant for a long time.... and sometimes they don't pass on to someone... but seriously, just because it could have been transmitted already (assuming there could be something) by saliva does not mean you should not use condoms for any kind of sex. Blood, vaginal secretions, and semen are the most dangerous fluids to swap for any kind of STD or STI, saliva is the least of the worries. There's always a chance... even though it's unlikely either of you has anything. It's also unlikely that when I'm backing out of my driveway that I'll need my seatbelt, but you never know, someone might come out of the blue and T-bone my truck, so I've always got my seatbelt on before my truck is in gear... if that makes sense.. you know, just because driving (or oral, anal, or vaginal sex) is more likely to get me into an accident than backing out (kissing or making out) doesn't mean I shouldn't be as careful as possible at all times. Although by driving, or having sex, I always assume the possibility of injury, but I enjoy both very much.

But honestly, it is unlikely either of you has any STD or STI... but do you want to take the chance?

[Purplebear]

I feel irresponsible, but you do have a point. It's so weird that sometimes, we can get really freaked out about pregnancy (always paranoid about precum on hands during manual sex, so we wash our hands regularly) but when it comes to STIs, I guess we have our blinders on.
I was, and am, still thinking about going down on him as a surprise for our third anniversary, but I think we need to talk about it a little more.
getting protection would be hard for us considering our age (both 15) and considering our parents, but i'll definitely give it more thought now.
There's still that part of me that's just like, really not wanting to bother with protection because of the small likelihood that one of us might have something. but you're right. it's always better to wear a seat belt.
I've just always looked forward to actually having oral and FEELING it like, in my mouth, and I don't like the idea of having a condom inbetween us like that when there's no risk of pregnancy. and I've always looked forward to FEELING his mouth down there, and I don't like the idea of having plastic wrap separating us. if that makes any sense.
how can I get over that dislike of barriers? it just seems like it wouldn't even feel good. (I wouldn't consider going without protection if we were having full-blown intercourse, don't get me wrong! but oral doesn't seem like such a risky activity. but I recognize that it is now.)

I'm sorry for rambling so much!