Terri, a 44-year-old substitute teacher from Alabama, said her manipulative mother-in-law makes her life a living hell.
"Our son, her grandson, gets whatever he wants from her even after we tell him no," said Terri, who didn't use her last name for fear the monster-in-law would recognize her. "The holidays are spent at relatives' houses with her talking bad about me behind my back."
Worst of all, said, Terri, her mother-in-law enables her husband by undermining efforts to get him to cut back on the booze.
"I tell him he needs to slow down," Terri said, exasperated. "Then the next thing I know, she goes out and buys him a bottle of Crown Royal for Christmas."
"This has been going on for 16 years now," she said. "She has even tried to get my husband to divorce me. I do not feel comfortable around her because when she pretends that she is behaving, she is scheming."
Terri is not alone.
A recent survey published by the website Gurgle revealed that 7 in 10 women say that their mothers-in-law are the biggest problems in their lives, questioning their parenting skills, barging into their homes and spoiling their sons and grandchildren.
Top complaints were criticism of child-rearing (39 percent); interference in daily life (23 percent); babying their sons (20 percent); spoiling the grandchildren (11 percent) and turning up at the house uninvited (7 percent).
In another study published last year by British psychologist Terri Apter, two-thirds of women complained that they had suffered long-term because of frictions with their husbands' mothers.
She described her two decades of research in the 2009 book, "What Do You Want From Me?"
Other studies show living with your mother-in-law can be downright dangerous.
A 2010 study from Harvard Medical School revealed that Japanese women -- who have a lower risk for cardiovascular disease than Americans -- were three times as likely to have a heart attack if they shared quarters with their husband's mothers.
In the end, it had little effect on the men's health, but the wives suffered coronary artery disease and a large number died of heart attacks.
Celebrities have mother-in-law issues, too.
Comedian Sunda Croonquist was unsuccessfully sued by her mother-in-law, Ruth Zafrin, for making her the butt of too many jokes.
And celebrity chef Gordon Ramsey has had a public feud with his mother-in-law, Greta Hutcheson, who threatened to cut ties with his wife, Tana, after he fired her husband and former business partner Christopher Hutcheson.
And the most stressful time for confrontations with in-laws is inevitably the holidays.
"There are two reasons, the unexpected visit and the gift-giving," said Beverly Freid, founder of the website Mother-in-Law Stories.
Her site gets 75,000 visitors from all over the world each month, 80 percent of whom are women.
Female readers report tactless gifts: a liposuction surgery gift certificate, pre-paid legal service for a divorce, samples from make-up counters, toilet paper, an outdated calendar, and maternity clothes for the daughter-in-law who is not pregnant.
Step children in blended families are often ignored entirely.
Others complain that mothers-in-law ask them to "step out of the picture" when it's time for a family Christmas card shot. Some were even asked to step out of their own wedding photos because "It's family only," said Freid.
She advises daughters-in-law to bring up differences early.