the dirty straw is when two people are making out, and one of them burps silently but does not stop kissing, and the result is that the one person blows their burp breath into the other person's mouth. this is called giving someone the "dirty straw".
"I was really turned on by Mike's kissing, until he had the nerve to try to get away with giving me the dirty straw. It was disgusting."
by John Muller January 08, 2006