I think we need:
1. We define whether the sim is LGBTQ or not. Then the Sim will reject the flirting of someone they are not attracted to.
2. The attractiveness system - let's determine who likes our Sim (back, body structure, eyes, hair etc.).
3. Traits affect who the Sim likes, eg a materialist will like a Sim who has a good job and a lot of money.
4. Sims will more often flirt with attractive people, but reject flirting from those who are unattractive.
I think it's logical and the game would be much more interesting.
I've found that premade marriages and Sims you bring into the game as a couple will be easier to flirt with each other. I do this: I bring marriage into the game, "divorce them" through MCCC, then give "forget all relationships" and then it's much easier to flirt because the Sims "remember" that they were a couple.
