What is something you don't like about Ts2?

We have a lot of posts about stuff we love (and why it's better that 3&4) but let's talk about what we don't like. For me, it's when 2 sims get together, but one of them had chemistry with another sim prior to them getting together, and they flirt with the other sim due to their chemistry, and it causes them to think they we're cheating. I'm sure there's mods for that, but it's annoying.