There is a lot of unknown here. Is she remorseful? Has the relationship been conflicted in the last few years? Do you have plans to marry? Do you have children? These things will all affect how you need to handle this. First of all, understand that it can take several months or longer to learn how to deal with the feelings of betrayal. It isn't as simple as saying "I forgive you. I'm over it." When you think things are going along really well, your devastated emotions will come back to haunt you. This is a normal part of the process following infidelity. She may also alternate between feeling regretful and ashamed, to saying you should be over it by now, to trying to blame you for why she had an affair. It is all more complicated because she had her affair in the home you both share, which means an invasion of your intimate space. This can feel like a double betrayal. Many couples find that couples therapy is necessary in order to work through the problem. Try to figure out what led up to the affair. How did the two of you became disconnected enough for a third person to come between you? One more thing to consider: In some long term relationships, the woman is wanting to marry, to make the relationship more permanent, but if the man is dragging his feet, she may find ways to manipulate him into "manning up", so to speak. Is this a possibility? Was she trying to force your hand? There is a book called "After the Affair" that might be helpful. I really do hope you can work it out.