I feel exactly the same way. I usually just make a horrified looking face. I can't believe they would do such a gross thing in front of a woman. One time I had to quickly jump out of the way or my foot would have received a coasting of phlegm. If I wasn't so shocked i really would have given that guy a piece of my mind. I do think it's cultural, as he looked surprised at my reaction (my horrified face). Maybe where he comes from it's acceptable to spit on someone's foot. Remind me not to go there.