Mark seemed to slip up while tweeting a friend, leaving fans wondering whether he had meant to send his digits in a private message, rather than post it in his feed.
"Yer ok mate give me a call when you are around. You had to DM me because I changed my number haha here it is...." he said, before posting a mobile number.
BUT it is April Fool's Day today, so we're wondering whether it really was the former TOWIE star's contact details.
Naturally, we couldn't leave you hanging, so we decided to give it a call and were met by Mark's voice in an answerphone message.
After ringing out, the message clicked in and he said: "Hi, you've reached Mark's phone. I can't get to the phone right now leave me a message and I'll call you riiiight back."
We didn't leave a message.
If it is an April Fool, Mark isn't the only celebrity to have played a prank today.
Earlier, the TOWIE cast pretended they were releasing a spin-off show called The Sloaney Way Is Essex, while Sheridan Smith fooled fans (but not us) into thinking she'd got engaged to musician Miles Kane.
Even Ricky Rayment, who is dating Mark's sister Jessica, got in on the act by whisking her to Paris and posting: "She said yes!!!!"
Ricky later admitted that Jessica had agreed to let him watch the football on the TV in France. She hadn't agreed to be his wife!
Have you been fooled today? Tell us below, as the best comment from across the website each week wins £50!