Oh, look at that. Simon is now worthy of Clary’s attention now that he’s a vampire and hot. Clary has never up to this point really took time out of her day to ogle Simon until now. Simon was always second fiddle, even after they got together. However, now that Simon is a vampire, he worthy of the time.
The reverse is the same of her relationship with Jace. Clary wouldn’t have given Jace the time of day if he wasn’t so hot. As I have said over and over again: Clary’s not in love with Jace, she’s in lust with his looks and is willing to put up with his horrible personality because Jace is so hot. In this universe, looks trumps everything else.
And isn’t that such a wonderful message to be pushing on young tween and teenage girls? ‘Looks are the only thing that matters.’ Not that your partner will respect you or actually give cares about you.