The former Vampire Diaries actress and the Bridge of Spies actor – who have been dating for seven months – recently ended their relationship because they are both too busy to see each other.
A source told E! News: “It started to get hard with both of their schedules. They remain on good terms.”
Before Austin, Nina was in a long-term relationship with her Vampire Diaries co-star Ian Somerhalder.
The couple split in 2013 and he went on to marry Twilight actress Nikki Reed last year.
And Ian recently revealed that he and Nikki are “absolutely” trying for a baby.
He shared: “Well, you know, those are the coolest little things in the world … Standby.”
Ian previously revealed he is ready to have children with his new wife.
Asked if he wanted a family soon, he said: “Oh, hell yes! Absolutely. You know, it’s all about practice… It’s not practice makes perfect – it’s perfect practice.
“It’s the most incredible thing to be happy and secure in something. It’s a pretty crazy time and place to bring a child into this turbulent and insane world – but I really can’t wait to do it and really just love it.”