Transsexual
To echo CAT, yep some do some don't. If thats what you like, you may want to start visiting a girl more often and once they feel comfy, they may let ya. I have met a very few who won't let you suck them with a condom and the same with you. That scares me.....The chance is still there. If you decide to venture that way, be sure not to floss before going into your session... 
Seriously.
YES there are ton's of girl's that are willing to COMPROMISE there health aswell as your's by engaging in unprotected oral sex
and yes it is relatively safe if your only concern is with catching hiv/aids seeing as how those two disease's(yes there's a difference between the two) are the only one's UN-documented to have been contracted during unprotected oral sex by itself, HOWEVER if you have concerns about any and EVERYOTHER DISEASE than NO IT IS NOT SAFE! and often time's they can go UNDETECTED
"Gonorrhea is spread through contact with the penis, vagina, mouth, or anus. Ejaculation does not have to occur for gonorrhea to be transmitted or acquired. Gonorrhea can also be spread from mother to baby during delivery."
"Since chlamydia can be transmitted by oral or anal sex, men who have sex with men are also at risk for chlamydial infection."
"HSV-1 can cause genital herpes, but it more commonly causes infections of the mouth and lips, so-called “fever blisters.” HSV-1 infection of the genitals can be caused by oral-genital or genital-genital contact with a person who has HSV-1 infection. Genital HSV-1 outbreaks recur less regularly than genital HSV-2 outbreaks."
ALL OF THESE QOUTE'S WERE TAKEN FROM THE CDC'S WEBSITE!
if you click the link i have attached to this post you can read up about the subject on the Center for Disease Control's website