Much like homoerotic this world holds it's passé under the bridge. When one is "emoerotic" they have a tendency to be emo, in much the same way as a homoerotic person has a tendency to be a brown-digger.
Emoeroticism is a variant of Emoerotic, but whilst still a noun, should be used in a sentence with correct grammar.
Below are some examples of how you would use the two words.
Matty: Ashley quit being so fuckin' emoerotic
Ashley: -Cries a river-
Matty: Man I have never been SO surrounded by so much bloody emoeroticism, I think I'm gonna puke.
Mike: I think I just puked a little in my mouth already.. Ewww..