There is a story among knitters, a superstition, even, that once you knit your boyfriend a sweater he will leave you.
The advice here is not to knit your boyfriend a sweater until he’s your husband.
But what is the reason for the boyfriend curse?
A. People knit their boyfriends bad sweaters and the boyfriends are repulsed.
B. The boyfriend doesn’t appreciate the sweater, however excellent it may be, and the knitter is repulsed. Since it is always the boyfriend who dumps the knitter in the story, this only works if he notices the repulsion and dumps her.
C. It seems like a commitment to knit a sweater, and the boyfriend is scared off.
The book Knits Men Want suggests another possibility. Sweaters, they think, trap men’s pheremones in their woolly fibers, rendering the guys madly attractive to other women.
The menfolks, suddenly surrounded by adoring women, are swept away… away from their loving knitter girlfriends.
I always enjoy a creative new hypothesis.