Dangerous...No. But if concerned see a Dr, can't tell you what it is. And no you should not worry about oral sex and STD's. Have your gf go get tested that might help ease your mind.
Thanks Vance. So i shouldnt worry about it? also one final question i have a small raised bump in my pubic hair, its very small, looks like a spot doesnt hurt. Could that be dangerous? thanks!!
Oral sex is low risk. If she gave her ex oral then it is possible she would have a STD if he had one, but it would be very low risk. I would not worry about it.