and Alev Aydin .
"It's an amicable split," a source told PEOPLE. "They're planning to co-parent."
The "Without Me" singer was first linked to the Turkish-American screenwriter in 2018 when he was tapped to write the screenplay for a biopic about and starring Halsey. However, the pair began a romantic relationship that curtailed the project.
In response to a tweet asking why the film never happened, , "bc alev was supposed to be writing it the past 3 years and we slowly fell in love instead. you know the rest!"
Halsey, who has been open about their , shared that they were expecting a baby with Aydin in 2021 after a previous miscarriage. "For a long time, I didn't think that having a family was something I was going to be able to do, and it's very, very important to me," the singer wrote in the .
The couple welcomed their son, Ender, in July 2021. According to court documents obtained by PEOPLE, Halsey is seeking full physical custody of the child following their split from Aydin.
From biopics and babies to their breakup, here is a complete timeline of Halsey and Alev Aydin's relationship.
Halsey and Aydin began working together on the singer's biopic sometime in 2018, but one of the first times they were spotted together in public was courtside at a Los Angeles Lakers game.
Aydin later posted about the experience . "Back when I did a very cool thing I'll prob never get to do again — massive thanks @iamhalsey for the courtside experience," he wrote. "Only ones not on our phones, actually watching the game."
The pair together in 2020, each getting the word "seeds" on one of their feet in the other's handwriting. California-based tattoo artist Amanda Owley shared photos of the tattoos on Instagram and later spoke to PEOPLE about the experience.
"She said that everything with how the planets were aligned and where the cosmos were at that moment indicated that it was the best time to plant seeds into the ground of life," Owley said. "They wanted to get the words on their feet because it was closest to the earth."
The artist also added that in addition to "laughing a lot the whole time," the couple practiced writing out each other's tattoos "about a hundred times" before landing on the right one.
In January 2021, Halsey shocked fans with a through a series of maternity photos on Instagram.
"surprise! 🍼🌈👼🏻," the singer wrote, in which they showed off their bare baby bump in low-rise baggy jeans and a crochet rainbow bra top. Halsey tagged Alev Aydin, who re-shared the announcement on his Instagram Story, adding a pair of red heart emojis.
In the comments under Halsey's post, Aydin wrote, "Heart so full, I love you, sweetness." Halsey replied, "I love you!!!!! And I love this mini human already!"
For the couple's first Valentine's Day since sharing their pregnancy news, Aydin shouted out the singer on Instagram.
" — us back before bebek (Turkish for "baby) was on the way," he wrote alongside a black-and-white photo of the pair on lounge chairs. "Happy Valentine's Day to the baddest woman on the planet — I Love You!"
Halsey responded by writing, "I love YOU my valentine!"
For Aydin's birthday, Halsey shared a photo of the screenwriter resting his head on their baby bump.
"İyi ki doğdun ❤️ , aşkım. ❤️ @zoneaydin," Halsey captioned the post, which included "happy birthday" written in Turkish. In the comment section, Aydin replied: "I love you, angel ❤️ my favorite person 😘😍."
Halsey and Aydin welcomed their son, , on July 14, 2021. Halsey shared the happy news with black-and-white photos of the newborn on Instagram.
"Gratitude. For the most 'rare' and euphoric birth. Powered by love," the singer wrote.
Along with releasing their highly anticipated fourth studio album, , Halsey spoke to Zane Lowe about being in love and how their relationship impacted the album's making.
"I love my partner, our relationship is so and communication," they said. "I remember having that moment when I was probably five or six weeks pregnant and being like, so what happens now? Do I have to be boring?"
The singer also said that pregnancy allowed them to finally slow down and take care of themselves. "Now here comes me, totally in love, the world's in shambles, but I'm getting arguably, the first break I've had in seven years," Halsey said. "I'm finally taking care of myself, eating my vegetables and getting sleep and I'm pregnant and everything's amazing and then out comes this."
Two months after welcoming their son, of their newborn's face with the caption, "the best birthday gift there is." In the shots, Aydin is holding baby Ender, who is wearing a multicolored onesie and a blue beanie.
Halsey and Aydin marked their with a sweet series of photos.
"Şişko boy is 6 months," the "Bad At Love" singer wrote alongside snaps of Ender fingerpainting and snuggling their dog, Jagger. "We celebrated with finger paints and a banana oatmeal cake and I made a little crown. He sorta just looks like the club kid Pope though... they said it would go by fast but sheeeeeesh."
In the music video for their new single "So Good," Halsey gave fans a with Aydin. Not only did Aydin direct and star in the video — it includes clips of the couple's real home movies.
"The film we created for 'So Good' really tells the full story of the song in the way I intended," Halsey said. "Alev and I were able to share a glimpse of the way that we fell in love: watching romantic films together. But this time, the [Samsung] Freestyle is playing real home movies from our life together. For us, this makes 'So Good' come to life in a really special way that we're so excited to share with fans."
In honor of Ender's first birthday, Halsey and Aydin on Instagram.
"my little tiny baby is a big one year old today! time flies, and I want to land the plane. permanently," the "Without You" singer wrote next to a series of photos of baby Ender. "Your baba and I love you so much. you are smart and fiercely determined and sweet and curious and funny."
Aydin shared a sweet message of his own along with a photo of the family of three. "PETIT PRINCE IS ONE TODAY!! Mama and I love you, Ender," he wrote. "To the moon, kid, to the moon."
After more than four years together, Halsey and Aydin have .
The "Bad at Love" singer is seeking primary physical custody of the couple's son, Ender, according to court documents obtained by PEOPLE.
"It's an amicable split," a source said. "They're planning to co-parent."