Gwyneth Paltrow and Chris Martin reunited on Sunday (06Apr14) to attend Robert Downey, Jr.'s birthday party as a family, weeks after going public with their "conscious uncoupling".

They were joined by son Moses, eight, and daughter Apple, nine, as they helped Paltrow's Iron Man co-star celebrate his 49th birthday at his Los Angeles home, and eyewitnesses insist the pair looked like any other married couple, despite recently announcing its split.

A source tells People.com, "They were lovey-dovey and playful. They were with the kids, they held hands and laughed and joked as a family.

"It was not the typical picture of a divorce. If the reports had not come out, you would think, 'Wow, they are a perfect couple.'

"Gwyneth was in such good spirits. She had her hair pulled back in a ponytail and she looked amazing."

Paltrow and Martin revealed they were ending their 10-year marriage late last month (Mar14), but insisted they would continue to co-parent and put their kids first.

The statement was published on the actress' Goop.com lifestyle website while the former couple was on vacation in the Bahamas with its children.