Erika has had a really rough day. She was talking with Robert earlier about their relationship and she got really upset because Robert ran inside and started telling Dana everything as soon as they were done. Erika was crying pretty much all afternoon and there were reports that she was packing and ready to leave, but she decided to stay in the house and tough it out.
I'm sure almost all the Hamsters will make a big deal out of something and threaten to leave at one point.