question: Hi doctor, I am really concerned to let a 50 year old guy who smokes cigarettes and marijuana, and drinks every day be sexually intimate with me. He touches me, pokes me with his hands and fingers, puts his tongue in my mouth, ejaculates over me on my skin, etc. If he does all these to me, could he pass the smoking toxins on to me and if not, what is the exact scientific reason for it? I do not think that brushing his teeth and using mouthwash would be adequate to remove all of the smoking toxins from his teeth, mouth, and tongue.