I had never heard of this one. "People with the unusual fetish can find it arousing to watch other people burp, or to burp themselves." It seems almost anything can become a sexual fetish. I better hide my wife from these people -- she has a great belch.

http://www.independent.co.uk/life-style/love-sex/inside-the-world-of-the-burping-fetish-community-a7435931.html