For once, everything seems to be going great in one of Martin's relationships. He and Kate couldn't be happier now that their sex problems are solved and they plan on living together at Martin's apartment. But, Kate can't quite understand why Martin and Judith still retain a warm friendship even after their divorce. As a show of good faith that that part of his life is behind him, Martin requests that Judith relinquish his extra key to their old/his current apartment. Judith does not react well – feeling issues of finality and abandonment about their relationship. Feeling sympathetic, Martin tells her to keep the key and that he will explain the circumstances to Kate, but actually has another key cut and presents it to Kate as Judith's. Then Judith decides to return the key back of her own volition which brings the three of them into direct confrontation, where it is revealed that Martin and Judith have slept together since their divorce. Kate storms out and Judith tells Martin she is having Richard's child. Martin apologises to Kate, but she tells him she can't move into his apartment, so he offers to move into hers. As the episode ends, Martin bids farewell to the apartment we've seen for the past three years and to the memories of he and Judith's marriage contained therein.