There are some underlying problems in that they don't see completely eye to eye on some things, and they aren't totally aware of this. It seems that Rob is pushing for something more to become of their relationship, while Anya is a little more hesitant. This comes across at the beginning of their conversation, when Anya says that she thinks they are trying to force their relationship. Rob counters that he thought they both felt like dating was a possibility. Anya goes on to say that they've been good as just friends. Anya is not directly saying how she feels, and seems to be skirting her true feelings, which is that she is more resistant than Rob about dating. In her commentary Anya also admits that although they used to always agree on important matters in life, recently they've begun to disagree on many important issues. Rob, however, still believes that they have the same views and aspirations. This demonstrates that they are not being totally open with each other.
One thing Anya can do to help with this situation is to be more up front about her true feelings. As for Rob, he should be careful not to blame Anya. He does this when he mentions her flirting. In blaming her he will only put her on the defensive, even if it is in a joking manner. Fortunately for them, they are both open to discussing the situation, even if they do not always fully disclose their true feelings. For the time being, they have agreed to keep having discussions about it. They will remain friends, but they are not ruling out the possibility for romantic involvement to develop.
One theory that helps explain this situation is Social Penetration Theory. As relationships develop, they go through various stages. Rob and Anya are probably in the "exploratory affective exchange" stage now. They have known each other for a long time, and are quite close. They disclose a lot of personal information to one another, and talk about their aspirations for the future. Many changes in their lives have pushed them to move on from this stage. Their relationship could take several courses. It could start to break down, and eventually end, or they could move on to an even higher level of intimacy. If their relationship continues, that intimacy would be quite different for them as friends than it would be as a dating couple. It is causing tension because as their relationship develops it is becoming more crucial for them to make a decision as to how it is defined. Whether they stay friends or start dating is a very important distinction for them to make if they ever want to truly stabilize their relationship.
Another theory relating to their situation is the Theory of Relational Dialectics. According to this theory, as Rob and Anya's relationship grows closer, there will be forces surrounding the relationship that pull against each other, causing tension in the relationship. In this theory there are 3 main types of relational dialectics, "connectedness and separateness," "certainty and uncertainty," and "openness and closedness." The first, "connectedness and separateness," seems to apply to Rob and Anya's situation. Anya noticed that after they started spending more time alone together the tension began. This could be due to a natural desire to be close to someone, while also feeling a desire to keep one's independence. "Certainty and