The tattoo, believed to be his 16th, is supposedly a tribute to his mum Pattie Mallette.
The teen popstar opted for a loving - if slightly creepy - tattoo of her eye on his inner elbow.
Below the snap, Justin said, "@bangbangnyc did this art ., Mums always watching ;)"
Yes, because that's just what you want, your mum always watching your misbehaving ways, Justin. Remember urinating into a restaurant's mop bucket? Not so sure she'd be so keen to see that...
Surely the 19-year-old must be running out of body space?
What do you think of Justin's new ink?
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