I have noticed in porn (both straight and gay) that a person will spit into another person's mouth (usually when getting a blow job). I was taught growing up that spitting was gross (though a lot of other things that I do now my parents would probably tell me is gross, but that is a different subject). While I am a open-minded guy and willing to try everything once (sometimes twice just to make sure that I really didn't like it the first time), spitting in someone's mouth is not any sort of a turn-on for me. Is it for anyone? Have you tried it, do it, or is it something you fantasize about?
I understand that it is no different from french kissing someone (which I have done more times than I can remember). I am curious to know what the turn-on is in doing it, and why it is not rare in porn.