He famously dumped her to shack up with Angelina Jolie.
And it seems all is not forgiven going by Laura Dern's expression as ex Billy Bob Thornton squeezed past her to accept his award at the Golden Globes in Beverly Hills on Sunday.
Social media erupted following the awkward incident, which occurred after he won the best actor in a television series gong for his Amazon show Goliath, in which he plays an alcoholic lawyer who fights for the little guy.
Unlike the 61-year-old's jolly demanour on stage moments later, Billy bob looked distinctly stony faced as he forced his way past his former fiancee on his way to picking up his prestigious paperweight.
A fan watching the episode on Twitter mused: 'At least we got to see Laura Dern physically fight the urge to stab Billy Bob as he walked behind her.
Another said: 'I'm convinced Billy Bob Thornton walked past Laura Dern just to piss her off.'
One wit injected levity into the moment, saying, 'Why wasn't Brad Pitt,Billy Bob Thornton,Laura Dern, Vince Vaughn & Justin Theroux seated at the same table? #MissedOpportunity.'
Cold shoulder: She did not look much amused as her old flame sauntered past
All smiles: He soon got over the awkward moment as he drank up the acclaim onstage
Billy Bob was in a relationship with the Blue Velvet beauty from 1997 until 1999, when he shacked up with Angelina Jolie.
The latter - who is 20 years his junior - became his fifth wife in 2000, however they were divorced just three years later.
He married his sixth and current wife Connie Angland in 2014 - which looks set to be his longest lasting union yet.
Meanwhile Laura sees parallels between the present-day political climate and her latest movie, The Founder, in which she plays the wife of the man responsible for putting a McDonald's in every town
Twit: Billy Bob was thoroughly mocked by viewers commenting on social media
Meaningful moment: Billy Bob seemed genuinely moved to have won the paperweight
Grin when you're winning: His awkward moment was the farthest thing from his mind as he flaunted his trophy backstage
She said: ''An American white male, a narcissist with a chip on his shoulder, decides that he needs to be the most important man there is, and he will do whatever it takes to become the top dog.
'He will take the country down with him.'
The Golden Globes ranks as the third most-watched annual awards show, behind only the Oscars and the Grammys.
The winners are chosen by the Hollywood Foreign Press Association and are known for springing surprises, as its members have no say in choosing the Oscars.
Young love: Billy Bob and Laura attending the Golden Globes together back in 1999
Happy memories: But just three years later he was attending with then wife Angelina