Ass to Mouth

I'm really love sucking "daddy's" big black cock and we both love when him and his friends take turns fucking me ass to mouth, "ATM". I only use coconut oil as lube and of course that makes their cocks taste amazing, I'm just sometimes concerned about the possibility of disease from doing ATM all of the time. I use the coconut oil because I read somewhere that it works like an anti bacterial agent and wonder if that is enough to make doing ass to mouth safe.