Ben Affleck and Jennifer Garner Reunite to Celebrate Daughter’s Birthday

Ben Affleck and Jennifer Garner may have called it quits last year, but the two have been keeping things amicable when it comes to their kids.

The stars came together over the weekend to celebrate their daughter Seraphina’s 9th birthday party on Saturday at their L.A. home, a source told PEOPLE.

“It was a small celebration,” the source said. “Ben was there too. Seraphina had friends over for cake. She got a lot of gifts.”

The two have been co-parenting their three kids, Violet, 12, Seraphina, 9, and Samuel, 5, since separating in 2015 and filing for divorce in April 2017.

Not only did the Affleck-Garner clan spend Christmas Day together, but the pair was also spotted taking a morning stroll together in Los Angeles in December. The family also celebrated Thanksgiving together.

Affleck continues to seek treatment for alcohol addiction. He “is doing well,” an insider told PEOPLE.

“He has been very on top of his health and responsible,” the source added. “He wants to be sober and healthy.”

Not only is Affleck growing healthier, things are also going strong with his new flame, Lindsay Shookus. The two were spotted together Friday afternoon.

“They seem great,” the source said. “You can tell they very much enjoy spending time together. They are very affectionate and giddy.”

Affleck began dating Saturday Night Live producer Shookus earlier this year. The Justice League star is reportedly paying for a New York City apartment for her and stays at the pad when he visits the city.

Garner, on the other hand, has struggled to open up to a new relationship following her split from the actor.

The 13 Going On 30 actress admitted she hasn’t “been on a date” since the longtime couple’s split.

“I would not have chosen this life for myself or for my kids. I would not choose to be single or be in this position,” Garner told News.com.au in November. “It’s something that we are working through. I haven’t been on a date and I am not interested in dating.”

After working together on projects like Pearl Harbor and Daredevil, the couple began dating in 2004 and were married for 10 years before their separation in 2015. She filed for divorce in April of this year.

When Affleck revealed in March that he had completed treatment for his longtime battle with alcoholism, he thanked his “co-parent” Garner.

“[She] has supported me and cared for our kids as I’ve done the work I set out to do,” he wrote in a Facebook post.