This is a short story from the early 1980s in Asimovs (probably still while edited by Scithers). The main character, an adult (20-something) woman has had a problem with small items of hers disappearing for most of her life - she and her boyfriend consider her to be absent-minded, but during the story, prompted by her boyfriend (I think) calling this phenomenon a "curse," realizes/imagines that items of hers are disappearing after she curses. The story ends with something annoying happening - the main character curses and then begins to realize that her boyfriend, who was around moments earlier, is no longer there.
This is "The Sorceress in Spite of Herself" (1982) by Pat Cadigan, published in Asimov's, December 1982.
The story starts with Lou hunting for her expensive diamond earrings, a gift of her husband Tony, in order to go our for her 30th birthday dinner. But she can't find them anywhere. This turns into a minor scene when Tony discovers she's lost them, and she thinks about losing things:
It was a scene they had replayed over and over through six months of marriage, with car keys, house keys, wallets, rings, eyeglasses, and a multitude of other things, usually hers, being the objects of the search. Long ago he had learned not to give her anything of his to hold, not even for a moment, because she would make it disappear. That was her special talent, making things disappear.
She is aware enough to realise that mostly she only loses things she doesn't want to lose, and to stop Tony laughing at her, she challenges him to put something valuable to him in her pocket. He chooses his wedding ring:
"You can look in my pocket now. I'm sure your ring is gone."
He looked. She kept her face averted as he stood bent over her pocket, transfixed. He made her stand up and patted her down the way cops frisked suspects on television. He felt around on the bed and on the floor underneath, crawling back and forth, digging his fingers into the nap.
At the restaurant, Tony comes up with the hypothesis that things disappear when Lou curses or swears:
"I made the association. Curse—cursing—swearing. Simple as that."
"There's only one thing wrong with that theory, bright guy. I didn't curse when your ring disappeared."
Tony's chin lifted abruptly. "Yes, you did. You said 'hell.'"
Partly because of the weirdness of the situation and partly because of their dinner being extremely late, Tony gets drunk and Lou has to drive home. Getting into the house, Lou trips over something and swears.
"Oh, goddammit!" she yelled, struggling to push herself upright.
Then she froze, leaning on the car, realizing what she had said.
"Tony! Tony!" She pushed herself around the front of the car, banging her knee on the bumper. "Tony, I said it! I slipped and said 'goddam', Tony, quick, wake up, we'’ve got to find out what I lost this time. The house keys—"
She yanked the car door open. The flash of the dome light hurt her eyes, and for several seconds she could only stand blinking at the empty front seat.
1thanks - but I can tell you're right, just from the title!– AndrewMar 12 at 21:24
2"A woman who has a history losing things has just lost a pair of expensive diamond earrings given to her by her husband. She was intending to wear them for their anniversary dinner. Husband finds out, they argue, she explains her “talent” and even manages to demonstrate it with his wedding ring. Over dinner, they discuss her talent and the husband decides it’s triggered by swearing – when she says “damn” or “hell”, or anything like it, items disappear." - sfmistressworks.wordpress.com/2014/10/16/…– ValorumMar 12 at 21:33
1it's SO Asimov :)– FattieMar 13 at 14:27