Semi open mouth kiss

Hello,
This forum is great and I learned a lot reading it. However, I still have a small doubt stressing me.
I promise that this will not be another question about kissing and Hiv. I read the archives, but I could not find a conclusive answer.
About my story, I do not know what I had in my mouth. I think a tooth was not doing too well and a section of my upper gums was swollen. In the past, I tried to blow this think a few times and something really gross (like puss) came out  (but not much blood, I think). Last May I semi-open mouth kissed an old friend. I cannot recall if I had or not that stuff in my mouth. Assuming that I had, should I be concerned? He kissed me maybe 5 or 6 times. Our tongues touched for no more than 5 seconds each time. How long has to be a deep and prolonged kiss to be considered risky?
Also, could you tell me if I understand  correctly?
a) French kiss is 100% safe only if both partners have healthy gums, lips, etc...
2)Otherwise, it could be risky. Why there is not agreement about this? Someone says " "no, risks", while someone else says "theoretically yes". This is my question: if I have an open sore, my gums are bleeding,etc, how much blood from the other mouth is needed to get Hiv in this way?

Thank you and sorry for my english!

[Teak]

You were never at risk not even if you had an abscess.

[bea195]

Thank you! I guess I was  "a little bit" confused with all the information you can find on line... or maybe I was just feeling guilty ( the guy I kissed wasn't my long time boyfriend).

Bea