Better title is:
Jeremy Soule's Soundtrack + HIV + MTV + Morons = Fail'd
Seriously, who the [censored] would eat gum off of anything of any surface?
Never heard of a metaphor? It is basically saying that, just like used gum on a bench, ashtray, etc., you never know where someone has been. Anyone and everyone can catch AIDS, it doesn't discriminate. It isn't saying "don't chew random gum." If that is what you got out of it, you weren't paying attention.