``Becoming involved in a relationship is a lot like being lured into a Hare Krishna cult''--so begins this long narrative necklace of good-natured one-liners posing as a novel of twentysomething love. Sasha Schwartz is a wisecracking young N.Y.C. ad-agency ``creative director'' in charge of writing toothpaste and paper- towel commercials. She spends her free time (i.e., most of the time her boss isn't watching her) talking on the phone with girlfriends Viv and Frannie and writing jingles about her ex-boyfriend, Bryce, who has recently left her--she suspects for a man named Glen, whose letters she's found in the apartment she and Bryce shared. (``Girl meets boy/Then boy meets boy/That's the story line these days/Oh, it's no joy/To love a gay,'' goes a typical ditty.) That's the plot; and the only event in the next 250 pages that could possibly be seen as an advancement of that plot is when Sasha runs into Bryce in a bar and is introduced to Glen, who is blond-haired, miniskirted, voluptuous, and very much a female. (Oh, well--so much Sasha's previous obsessional worries about AIDS.) Otherwise, the book is a jumble of Bob Dylan quotes mixed in with bathetic reminiscences of Sasha's childhood, Viv's phone harangues, rejected ad copy, rash jokes, secondary characters' glowing assessments of Sasha's talents, character, and looks, one whole chapter devoted to numbers (``461, 462, 463...'') representing Sasha counting sheep as she tries to forget Bryce and sleep--and three or four authentically funny moments, all of which take place in the presence of Sasha's personable fellow ad-agency worker Jerry, known as ``Jerriatrics.'' A pinch of promise in a sophomoric brew--and hardly the work of the ``Nora Ephron of the MTV generation,'' as the publisher's promo copy claims.