When conversating with another Sim, if you press the wrong button they will get mad at you. Here's something that I hope will help you decide what to push.

When the Sim is mad press comfort to raise his bar the most.

When the Sim is calmed down a bit, talk, listen, and encourage him. Do not laugh or he will get mad again.

When the Sim is happy music notes will appear. This si the best time to laugh!