I'm also a teacher (retired) and single parent (12 y/o girl) who needs occasional kid-free time just as you do. This is precisely why I stay away from known kid-pleasers like Carnival and MSC during major holiday break time unless I'm with my kid. If you really prefer adult company during that time, try Celebrity or Holland-America. Note: if a ship has a waterslide, it's going to have a lot of kids. Also, MSC and Costa, being European, have a more lax and leisurely attitude toward children because that's how they parent. The things that we may find rude and inconsiderate in their children they find snobbish, stuffy and overbearing in ours. Two sides to every coin.