When you watch the Big Bang Theory for any length of time, you are going to be surprised with what you learn about the characters. In most cases, you have the opportunity to laugh at what they bring to the table but they also have a serious side as well. In some cases, you get to take a look behind the scenes, so to speak, and learn something juicy about what has taken place in the plot.
In this skit, Amy and Penny are sitting around talking with Bernadette and the subject turns to how Amy got pregnant. Nobody was expecting any real details but they ended up learning something that really caught their interest. It seems that Bernadette and Howard had a spontaneous moment when they were visiting Sheldon and ended up slipping away for a moment. It really takes Amy and Penny by surprise.
The Big Bang Theory is a great mixture of everything that makes a sitcom interesting. Not only does it make us laugh at what is taking place, we also get to watch as the show continues to develop. No wonder it has been on for 10 seasons.