Imagine if these guys doesn't have their Mustache? Mustache gives a guy more tough looks and masculine though gay people have mustache too. Famous Man like Che Guevara was known for his Mustache, without his mustache he looks like some common rebel.
Check the guys With and Without their Mustache
Anyway with mustache it gives more define character, remember Jose Rizal has mustache making him Macho-Gwapito (sexy good looking guy), now wonder she collected a lot of girl friends around the world.
Jose Rizal Mustache, at its best since 1800's
Chuck Norris Mustache has never been explored by man
Weird Mustache that you don't want to have
The Onion Ring / The Spring
The Dress Hanger
The Hair Mustache
The 'We Hate Our Mustache'