The model and Coldplay star have kept in touch since they made friends at Glastonbury last year and if recent reports are to be believed, they've become even closer since Gwyneth Paltrow announced their "conscious uncoupling" in March."
How did it go? A source told the magazine the friends were getting on well.
"When I arrived at about 9.15pm, they were tucked away in a dark corner of the back room of the bar," the source said.
And what will Gwyneth think? Despite their recent split, Paltrow and Martin are still on good terms. The former couple were recently seen on a dinner date in Los Angeles and looked to be having a great time.
"Gwyneth and Chris were in a great mood, laughing and sharing some wine," a source told the New York Daily News.
"Everyone in the restaurant definitely noticed them but they didn't draw attention. It looked like these was no bad blood between them at all."
Want to find out more about the Alexa and Chris dating rumours? See the full story below:
See more of Martin's ex Gwyneth in her style file: