Googling the letters CBT pops up several meanings of this acronym. But for gay men these initials have only one meaning, cock and ball torture. For those who don't know, CBT is defined as the sexual actions of male genitals being tortured. Examples include genitals being squeezing, tickled, typed up or even hot waxed. The person having their genitals tortured enjoys the pain and emotional pleasure from this activity.
Other than paid sites, there is not a lot of CBT websites on the Internet. One exception is tumblr, which hosts a handful of CBT material. One such site is CBT Master, which is run by Rope Life. There is no text, as it only features photos. Some of the images are some of the most explicit and cringe-worthy CBT encounters you will see. If CBT turns you on, go to the site now. But if seeing men's genitals tied up and tortured, best you skip this.