The pair, who have been fueling romance rumors since October, quietly made their way into Stella McCartney’s Autumn 2018 Collection in Los Angeles through a private entrance, skipping the red carpet and cameras for a low-key date night together.
While Johnson and Martin were shy about walking the carpet, they were not shy about showing their affection for one another inside the event.
“They walked in holding hands and Dakota was not letting go – she was super into the PDA,” an onlooker tells PEOPLE. “When Chris let go of her hand, she slipped her arm through his.”
The Fifty Shades Freed star, 28, – who was previously linked to model/rocker Matthew Hitt – wore a sparkly dress with her hair in a high ponytail while the Coldplay frontman, 40, dressed in a long sleeve shirt and pants that was accessorized with a baseball cap and scarf.
And their affections did not end there with the pair enjoying a sexy song.
“They had their arms around each other during Bruno Mars’ song ‘Finesse.’ Chris bobbed his head around as she leaned into him,” the onlooker says.
Saying at the event until performer Beck finished his set at 11:30pm, “They didn’t leave each other’s side,” the onlooker says.
While the ex-husband of Gwyneth Paltrow appeared to be “super chill” he also seemed “attentive” to Johnson, who is the daughter of actors Don Johnson and Melanie Griffith.
WATCH: Gwyneth Paltrow, Ex Chris Martin and Her Rumored Fiancé Brad Falchuk Grab ‘Sunday Brunch’ Together
This outing comes after Johnson and Martin were spotted walking arm-in-arm on a Malibu beach together.
They spent “most of the weekend together in Malibu,” a source previously told PEOPLE.
“They seem to be getting more serious. On Friday, they had dinner with friends. They also hung out at Chris’ house and went for a beach walk. They didn’t see each other over the holidays and seem excited to be catching up now,” the source shared.
Also this month, Johnson and Martin were spotted grabbing food and drinks at Soho House in Malibu.
“They met up with friends and had a fun night. They both seemed very happy. They were flirty, and also left the restaurant together,” an insider told PEOPLE about their Jan. 12 outing.
Johnson and Martin first sparked gossip of a blossoming relationship after being spotted on a sushi date in Los Angeles in October. Then, in November, the actress was photographed by fans hanging out in the sound booth at Coldplay’s concert in Argentina.
Martin shares two children with Paltrow: 13-year-old daughter Apple and 11-year-old son Moses.