I Don't Know What's Going On!

I don't know what's going on but I'm completely worried. I've been analyzing the evening and finding probably nonexistant problems. My mom sent us kids out to eat and we went to Mongolian Barbecue. Right before we left my sister came downstairs and mouthed, "Dad's home." and then we took off. I didn't realize anything was going on, but then on our way home my dad called my sister on the phone and their conversation had something to do with something someone had told my two siblings, and how the someone hadn't told me. I think the "someone" is my mom. I'm not sure what the "something" is but I'm worried it might be divorce. See, last spring my dad threatened to file a divorce and that was the first I knew of any marital problems, but I'm probably not that intuitive, so I might not have picked up on anything. Ever since then my mom has been explaining and complaining about their marriage. I'm really worried and my parents aren't home and I don't know what to do. Ok, I'm done. Oh I'm so worried!