people enjoy tamakeri because they either feel good feeling pain or making others feel it. the feeling is like a "runner's high", where feel-good hormones called endorphins are sent out by the body. these endorphins make the people involved feel sexually aroused. but some people say that threats and more painful kicks or knees to the testicles by the female (in straight people) makes people more aroused. belonging to a dominant boyfriend or girlfriend can also be a "turn-on". like a lot of bdsm activities, it can be risky, and those involved can get hurt.