Kate Hudson and Matt Bellamy reunite for son's birthday

Former lovers Kate Hudson and Matt Bellamy have reunited to celebrate their son Bing's fifth birthday.

The ex-couple took their boy and Kate's 12-year-old son Ryder to watch the play Harry Potter and The Cursed Child in London on Saturday (09Jul16). The show is currently in previews, and officially opens at the end of the month (Jul16).

The 38-year-old Muse frontman posted a shot of the foursome in front of a poster for the play on Instagram, adding the caption: "Happy Bday Bing!!! #harrypotterandthecursedchild @katehudson xxx."

Kate later reposted Matt's shot on her Instagram page, and added, "Bday (sic) time" with a love heart emoji.

The 37-year-old also documented her little boy's birthday on Snapchat, where she revealed what presents the youngster had received. She shared a video of the family playing with one of Bing's more expensive gifts - a remote-controlled BB-8 toy from the movie Star Wars: The Force Awakens.

The toy, which retails for around $150 , not only moves but can record and send videos. "Hello? Hello?" she says to the toy in the clip. "OK, so... does it move? It's so cute. I love him."

Kate and Matt began dating in 2010, and became engaged a year later before welcoming son Bing in July, 2011. Their split was announced in 2014, with Matt spokesperson saying at the time, "Kate and Matt have been separated for some time now. Despite this, they remain very close friends and committed co-parents."

They have remained friendly since their amicable breakup, and in March (16), Matt joined Kate and the kids to celebrate Easter with her extended family, including her mom Goldie Hawn and her longtime partner Kurt Russell.