The X Factor judge showed her commitment to the footballer by visiting the Demon Ink Tattoo Parlour in Newcastle on Thursday (February 7).
The singer had her tattoo on her lower back, while the Newcastle United defender had one on his torso. Tulisa appeared to take charge of his inking in pictures posted online.
"New tat is aching 2day, worse then havin it done, (sic)" she later tweeted.
The pair, who have been dating since November last year, are yet to reveal exactly what they had tattooed. She recently flew home from Spain to support him after he was attacked during a night out in Manchester.
Tulisa already has a number of tattoos, including The Female Boss inking which she shows at the beginning of each X Factor live show as part of her signature arm gesture.
The move was famously investigated by Ofcom following claims it constituted advertising her perfume of the same name.