Algernon: Why is it that at a bachelor's establishment the servants invariably drink the champagne? I ask merely for information.
Lane: I attribute it to the superior quality of the wine, sir. I have often observed that in married households the champagne is rarely of a first-rate brand.
Algernon: Good heavens! Is marriage so demoralising as that?
Lane: I believe it is a very pleasant state, sir. I have had very little experience of it myself up to the present. I have only been married once. That was in consequence of a misunderstanding between myself and a young person. (I.9-12)
The main idea, here, is that marriage is demoralizing. This seems to be a recurring motif throughout the play. Lane doesn't think that marriage is "demoralizing", but then again, his marriage wasn't really a marriage.