Chris Martin and Dakota Johnson are reportedly expecting a baby.

The Coldplay frontman and the 'Fifty Shades of Grey' actress have been dating for just over a year, and are now set to take their relationship to the next level as Dakota is said to be pregnant with the pair's first child.

According to TMZ, 29-year-old Dakota and Chris - who already has daughter Apple, 14, and son Moses, 12, with his former wife Gwyneth Paltrow - threw a gender reveal party for their unborn tot at Chris' home on Sunday (07.09.18).

Pictures obtained by the publication show blue and pink balloons tied down in arches, as well as depicting the star-studded guest list for the event, which included Sean Penn, Julia Roberts, and Dakota's parents Melanie Griffith and Don Johnson.

TMZ reports that Don was the last to arrive to the bash, and 10 minutes after he got there, a stream of blue balloons were released into the sky, signalling that Dakota and Chris, 41, are expecting a baby boy.

The baby news comes just one week after Chris' ex-wife Gwyneth tied the knot with her new husband Brad Falchuck.

Previously, 'Suspiria' actress Dakota played coy about her romance with the 'Viva La Vida' hitmaker, but said she was ''happy''.

She said: ''I'm not going to talk about it. But I am very happy.''

And whilst they might be doing what they can to keep their relationship out of the spotlight, Dakota's parents are more than happy to gush about their daughter's beau.

Melanie said in May: ''I adore him! But she is very private about her life and I respect that.''

Whilst Don gave his support for Chris when he said: ''He's a lovely guy. I've met him and you want your kids happy, no matter what shape it takes.

''That's the goal, that's the key. He's a very talented and gifted musician. I've seen them in a concert at a small venue called the Troubadour in Los Angeles when they were first coming out and that was a memorable moment.

''I knew right then he'd be good for her. I said 'Oh you know, that man has got something going on'.''