Ok, let me start off by saying this will probably be one of the most freakish/stupid movie scene you'll ever see. Its a HK movie about sex curses and evil chinese wizardry, in this scene you'll see chinese wizards dueling, a good wizard vs an evil wizard couple, guess how the evil couple harness their powers? no, not harry potter style, they get their powers by fucking the shit out of their partner, they start off by kissing each other (5:23) and...
you know what? just watch the fucking thing
https://www.youtube.com/watch?v=F6sTaps4gM4
i recommend watching the whole thing from the beginning, theres a pretty cool part where one of the guys got his head transformed into a PENIS, for serious. its just nine minutes, and dont worry theres english subtitles so you'll know whats going on