Thai Flame Thrower
Earliest form from males in Thailand. A Man and a woman prepare for intercourse after dinner. The man chops up a hot pepper like a jalapeno to use for the dinner and handles the jalapeno (hot chilli pepper) and doesn't wash his hands. Then proceeds with intercourse via manual stimulation with his fingers in her vagina. May include coitus.
Thai man and woman finish having sex. They both complain of a burning sensation, and they are sure they do not have an STD or a rash. Man asks his partner "how was it?" Woman replies: " That must have been so good. It's still burning." Man "I thai flame thrower-ed your ass". Or " I brought the heat."