"It's actually cool but you shud put it somewhere else," one user commented. Another concerned fan weighed in, simply writing, "Why" with a devastated emoji.
The initials are interesting, which got fans thinking: Is it homage to his mom, Tricia Brannan Malik? Or could it, in fact, be in celebration Mind of Mine?
Malik, 23, has yet to weigh in on whether it's real or not (and what it means!), but seeing as his other tattoos are quite diverse -- he has ZAP! inked on his forearm and a portrait of his ex-fiancée, Little Mix's Perrie Edwards, on his right bicep -- we wouldn't be surprised if it were permanent.
One thing we know for sure? Malik appears to be head-over-heels for his new girlfriend, supermodel Gigi Hadid. On Friday, the singer took to Twitter to share a photo of his blonde beauty flashing a smile and major side boob.
"Saw your face and got inspired," he adorably tweeted.
Malik hasn't been shy about the 20-year-old model. When ET caught up with Hadid at the Sports Illustrated Swimsuit Issue party in New York City last month, she revealed her beau was a big fan of her bikini-clad pics published in the special issue of the sports glossy.