They work at the same company but in different departments. She says the affair happened only once and I do believe her. She was genuinely remorseful and apologetic for lying to me and for hurting me. I don't believe she feels sorry for sleeping with another man. I think she feels like she was somehow justified in doing that because of all the troubles we've had in our marriage.
What troubles me most is that she says she is no longer attracted to me physically. Everything else in our relationship works great. Everyone who knows us believes we are the perfect couple and if you take sex out of the equation, they're right. She feels as though she needs to go elsewhere to satisfy that need/desire.