Lena Dunham and Jack Antonoff have split.

Lena Dunham and Jack Antonoff in 2014

Lena Dunham and Jack Antonoff in 2014

The 31-year-old actress and the musician had been dating for five years since they first started romancing one another in 2012, but according to sources, they decided to mutually call time on their relationship in last month.

An insider told E! News: "It was mutual. Jack and Lena were growing apart and it just made sense for them to end their relationship where it was. They want the best for each other no matter what. They are both moving on."

Despite their lengthy relationship, the 'Girls' creator and Jack, 33, had never felt rushed to progress their romance and become engaged, and Lena previously said she was pleased at the lack of pressure the pair had put on their relationship.

She said in February: "I am not against marriage in any way, but I do like the fact that Jack and I have placed zero pressure on ourselves about it. I have friends who have met someone, married them and got divorced during the period of time that Jack and I have been dating. We are as close as you can get to a pair of 100-year-old people. Every night we go home, walk our dogs, put them into their crates, take melatonin, watch 20 minutes of TV, then we go to sleep. It is the schedule of ancient, ancient people."

But even though she never married Jack, Lena admitted she still felt the pressure from other people to be the "perfect partner" for her former beau.

She explained: "Even if you're a woman without children, there's so often an expectation that you're going to go to work, and be the perfect partner to your boyfriend, and show up cheerfully at all of his work drinks, and remember everyone's birthday, and get to every baby shower, and take care of the cat, and make sure you have toilet paper. It's just too much."

As of the time of writing, neither Lena nor Jack have publicly commented on the news.