There's something joyful in this 10-second clip, if you can put aside that these two men are about to do their best to beat the crap out of one another. Is it the sly grin on their faces after the kiss? You decide.
You might think that a professional boxer with the gonads to kiss his opponent would carry an advantage in the arena. And alas, you would be wrong. According to a curious posting ("A Brief History of Fighters Kissing Their Opponents") on Sherdog (a very butch, testosterony site devoted to martial arts), the kiss-er has a solid record of getting knocked out by the kiss-ee, historically.
So, maybe homosexual panic is good for your upper cut?