I feel they may have recently either broken or modified the mechanics of romance.
There was another thread saying all Sims are bisexual now. I got curious then and loaded up my game to play a character with the Vampiric Charm power. Sure enough, I personally remember it only used to work on the opposite gender, whereas now it was hitting everyone.
As I said, I'm not sure if it's intended or a bug, but either way these changes to romance sure seem to be annoying a lot of people.