Saliva is one of the few things tthat triggers my gag reflex like crazy. It's one of the germiest fluids one can possibly produce, of course it's disgusting.
There was this one time I was in the car with my sister and her boyfriend. I was in the backseat, smoking, so my window was open, as was hers. We were on the highway and she spit out her window (she was in the passenger seat) and it went right back in my window and hit me on the side of my face and neck.