 Frasier and Lilith announce that they are moving in together and as the instigators of the relationship, they invite Sam and Diane over as their first dinner guests. Just prior to Sam and Diane s arrival, the new couple analyze their relationship and who manipulated who into doing what, which starts an evening long argument. As Sam and Diane arrive, the evening goes on a roller coaster of emotions, the major downturn initiated by Diane revealing to Lilith that she and Fraiser were once engaged, something that Frasier had not yet mentioned to Lilith. Thus Diane becomes the third member embroiled in the emotional battle for the evening. Sam ultimately becomes the voice of reason calming everyone down. As the evening looks to come to a final calm end, both Lilith and Diane storm into the bathroom over other separate issues, to which Frasier finally takes matters into his own hands.