Ben Affleck split from Lindsay Shookus because of the distance put between them by their careers.
The 46-year-old actor and the 'Saturday Night Live' producer had been dating for over a year before they were reported to have gone their separate ways this week, and it has now been claimed the romance "didn't work out" because they both have obligations on opposite sides of the US.
A source said: "It was amicable, but unfortunately it didn't work out, partly because of work and family obligations on different coasts. They truly cared for each other and tried to make it work. Unfortunately now is not the time."
The 'Justice League' actor is based in Los Angeles for work and to be close to his three children, Violet, 12, Seraphina, 10, and Samuel, six, whom he has with his estranged wife Jennifer Garner.
Whilst Lindsay, 38, lives across the country in New York where she works on 'Saturday Night Live' and also co-parents her five-year-old daughter, whose father is her ex-husband Kevin Miller.
Despite their split, Ben is said to be "doing well", and is in a "good place mentally".
The source added to People magazine: "Ben is doing well. He is in a good place mentally and has worked really hard to get here. He continues to focus on himself and the health of his relationships."
Ben and Lindsay's split was first reported earlier this week, following snaps of the 'Argo' star on what appeared to be a date with 22-year-old Playboy model Shauna Sexton.
A source said at the time: "They really tried to make it work and they just couldn't right now. Their families came first, but ultimately having a bi-coastal relationship was difficult. They're amicable."
Meanwhile, it was claimed earlier this month that Ben and Jennifer have been "dragging their feet" over their divorce, prompting a warning from the courts to speed up the process.
The couple announced they were going their separate ways in June 2015, before filing documents two years later but they are said to have angered the court by delaying divorce proceedings.
Los Angeles Superior Court is said to have told the former couple that their case is not completed because the final judgement hasn't been entered and it could be dismissed in its entirety.
The court is said to have told them: "If you fail to take the appropriate steps in your case, the court may dismiss your case for delay in prosecution."
Tagged in Ben Affleck Jennifer Garner