Story in answer to a prompt on Norsekink:
Let us assume that Thor, being big with golden hair and blue eyes is the Asgard ideal man.
Now let us assume that Loki is not. He's got the height but not the muscle, his hair is black and what's with the green eyes? Green? Seriously, yuk!
Anyway, due to everyone on Asgard thinking Loki is actually quite hideous he has never managed to talk anyone into going to bed with him, either as a one night stand or a serious relationship. He tried hard in the beginning but the constant polite declines (and private ridicule that he listened in on) were too embarrassing and hurtful and eventually he just stopped trying.
Okay, so Loki's got the worst self esteem in history and is convinced he's the ugliest thing ever to walk Asgard. Now he's on Earth and fighting the Avengers.
(Continued in notes)