Angry Sims can kick a bin over and knock the trash out from it, they can also destroy dollhouses.
Sims will think their Spouse is cheating on them, even if their Spouse is actually being faithful when other Sims try to flirt with them.
I don't know if this is fully true or not, bad Sims with a bad relationship will often not sit next to each other if the table is long enough.
Sims who are Sad will often reject Romantic Interactions from other Sims.
Sims will gasp if they see their Spouse Woohooing with someone else.
If Sims get Divorced and you click on their family tree, their Spouse will no longer be there but in each of their family trees they'll still be a parent to their Child - Might only happen with Adopted Children.