In Ch. 33 Elinor & Marianne meet up with their brother. John is impelled to tell a few lies when politeness requires it. (:D) He tells Elinor that he and family have been in town for two days and explains his neglect by assuring her of his thwarted desire to call upon them immediately:

"I wished very much to call upon you yesterday," said he, "but it was impossible, for we were obliged to take Harry to see the wild beasts at Exeter Exchange: and we spent the rest of the day with Mrs. Ferrars. Harry was vastly pleased. This morning I had fully intended to call on you, if I could possibly find a spare half-hour, but one has always so much to do on first coming to town.

Thwarted it appears not by time but by his wife and mother. Later John lets it slip that the real reason was because Fanny and Mrs. Ferrars feared the Miss Dashwoods had fallen into unmentionable unacceptable company that was unworthy of their attention and a connection that would surely be a degradation to themselves:

"I shall have a charming account to carry to Fanny," said he, as he walked back with his sister. "Lady Middleton is really a most elegant woman! Such a woman as I am sure Fanny will be glad to know. And Mrs. Jennings too, an exceeding well-behaved woman, though not so elegant as her daughter. Your sister need not have any scruple even of visiting her, which, to say the truth, has been a little the case, and very naturally; for we only knew that Mrs. Jennings was the widow of a man who had got all his money in a low way; and Fanny and Mrs. Ferrars were both strongly prepossessed that neither she nor her daughters were such kind of women as Fanny would like to associate with. But now I can carry her a most satisfactory account of both."

John, with all the finesse of a walrus on land, tip-toes around Fanny’s and Mrs. Ferrars’ self-interested anxiety over Elinor’s status and her designs of drawing Edward in:

Colonel Brandon must be the man; and no civility shall be wanting on my part, to make him pleased with you [Elinor] and your family. It is a match that must give universal satisfaction. In short, it is a kind of thing that" -- lowering his voice to an important whisper -- "will be exceedingly welcome to all parties." Recollecting himself, however, he added, "That is, I mean to say -- your friends are all truly anxious to see you well settled, Fanny particularly, for she has your interest very much at heart, I assure you. And her mother too, Mrs. Ferrars, a very good-natured woman, I am sure it would give her great pleasure; she said as much the other day."