According to Starwatchbyline, here is a short summary of ep 12:
Leonard and Penny go visit a psychiatrist as part of her sales call and learn some things about their interaction (each on their own), and find it helpful. Amy is off at a conference while Sheldon and Raj, at the Telescope manage to locate a mid-sized asteroid in their pursuit to find a new planet. Sheldon receives a couple of Skype calls from Amy where they share loving exchanges (no mention of their coitus, but still clear they are in love.) Stuart moves out of the Wolowitz home and Howard and Bernadette realize how much they miss him after he is no longer living there.