The TV chef's ex-husband Charles Saatchi is now dating fashion expert Trinny, who appeared to mock Nigella in a blog marking her 50th birthday, seemingly making reference to when Charles put his hand around his ex-wife's neck at a London restaurant last year.
Trinny wrote: ''It's great that, at 50, life can still grab you by the throat and shake you up.
''And it's even better when you've learned to cope with whatever's thrown at you -- so long as it isn't a bedside lamp.''
The star, who is celebrating her birthday in the Lake District with Charles, then had another dig at Nigella, 54, who is known for her curvy figure, writing: ''If you used to like showing your cleavage, just be aware your skin probably looks like old chammy leather now.
''So wear something round-necked. You can still show off your shape.''
Nigella appeared to respond to the blog post by writing on Twitter: ''Slut's Spaghetti -- aka pasta alla puttanesca -- is #recipeoftheday. Do I need to say anything more? (sic)''
The brunette beauty attached a photograph of the recipe, before later adding: ''No agenda behind #recipeoftheday! Slut's Spaghetti an old fave of mine. (sic)''
Nigella married wealthy art dealer Charles in 2003 but they divorced seven weeks after photos emerged of him with his hand around her neck in 2013.
The break-down of their marriage was played out in public during the trial of her former aides Elisabetta and Francesca Grillo, who were acquitted of fraud last year, where Nigella was forced to admit she had used cocaine and marijuana in the past.
He also slapped a jet-lagged Taylor Hawkins.
The acclaimed performer had just cancelled touring due to a battle with cancer.