Despite recently denying that he and Jacqueline had rekindled their romance, Dan tweeted the actress last night saying that he "missed" her while in Spain.
Jacqueline, who plays Lauren Branning in the BBC1 soap, then replied - sending the 'are they/ aren't they' rumour mill into overdrive!
Dan flew out to Marbs with his TOWIE cast mates on Saturday, however he tweeted Jacqueline saying: "Miss you @jacquelineMjos." Posting a blushing emojicon, she wrote back: "@DannyO miss you too xx."
At the end of last month, Jacqueline and Dan were spotted hanging out together in Borehamwood, Hertfordshire, and were all smiles as they chatted together.
They had originally become an item after meeting on Twitter, although they split because Dan was expecting a baby - his son Teddy - with his ex-girlfriend.
Reveal has contacted Dan's rep for a comment.
Meanwhile, Jacqueline isn't the only person Dan is missing. Yesterday, the reality star posted an adorable picture of baby Teddy on Instagram.
Alongside it, he commented: "I miss my little man so badly." Aww!
Watch the new TOWIE trailer here: