The clear sign that Harry Styles is serious about Zoe Kravitz has been revealed after she supported him at the Berlin Marathon.
The singer, 31, joined 50,000 runners for the 26.2 mile race last weekend with the actress, 36, there cheering him on as he crossed the finish line with an impressive time of 2:59:13 hours.
But in a clear sign things are serious, Zoe has remained with Harry in Berlin during his time there.
The couple were first linked in August when they were spotted enjoying a romantic stroll in Rome.
So far, their whirlwind romance has brought them to Rome, Tuscany, London, and New York City to meet Zoe's family.
Meanwhile, Harry is said to have been in Berlin working on his fourth studio album, which could be set for release in 2027.
A source told The Sun: 'It's no secret that Harry is making his new album in Berlin and he's been getting lots of inspiration from the music scene there.
'The fact he wanted Zoe to join him just shows how important she is as part of the creative bubble process for him and how much he wants her to be part of every aspect of his life. He doesn't share his music with just anyone.
'He's spent a lot of time in the city and it's really special that he's getting to show Zoe his secret life there. This is really a sign of just how serious things are with them.'
Harry and Zoe seem to be regularly spotted walking around various places in Europe in a 'promo' trail of their relationship, wearing carefully planned matching ensembles.
While there's nothing to suggest their romance is a publicity stunt, it's clear they don't fear being seen together and if they're being seen, they're doing it in style.
During their time in the Big Apple, Harry and Zoe spent time with each other's friends, and he was even introduced to her world-famous father, Lenny Kravitz , 61.
The couple were given an opportunity to meet members of each other's social circle while dining out at the New York branch of Wolfgang Puck's celebrated Cut restaurant, housed within the exclusive Four Seasons Hotel.
Onlookers claimed spirits were high as Harry let his hair down with Zoë and their wider circle of pals over dinner and drinks at the upmarket eatery.
The Daily Mail revealed pals close to the couple say they are 'kidding themselves' if they think it's just an innocent fling, and exclusive pictures certainly prove they're very much in sync with one another.
Harry's previous romances include Olivia Dean, actresses Taylor Russell and Olivia Wilde, French model Camille Rowe, food blogger Tess Ward, singer Taylor Swift and the late Caroline Flack.
Onlookers claimed their appearance in New York last week was 'intense,' with the pair holding hands and wrapping arms around each other during an afternoon outing.
'This is brewing into something more, whether they think it is or not,' a source told the Daily Mail.
'They both like each other, and friends don't know who likes each other more, but it is turning into something more than just a casual situation.
'They might not want to think it is, but surprise, surprise, it is getting interesting.'
The insider added that Harry and Zoë may be growing more serious as they reach an age where playing casual is no longer appealing.
'Even with the lack of labels, or labels that aren't official boyfriend and girlfriend status, they are just kidding themselves; their friends see this could be something special; if they want to make it into that they should. No reason to play games.'