It was confirmed last week that the former One Direction singer, 27, and supermodel, 25, were expecting their first child together, reportedly a daughter, in September 2020.
Pillowtalk hitmaker Zayn revealed what appeared to be a new tattoo on his left forearm featuring the poem On Marriage by poet and philosopher Kahlil Gibran.
It reads: 'Sing and dance together and be joyous but let each one of you be alone.
'Give your hearts, but not into each other's keeping. Stand together, yet not too near together; For the pillars of the temple stand apart.
'And the oak tree and the cypress grow not in each other's shadow.'
The poem is a popular reading choice at weddings.
The photo was shared by jeweller George Khalife who recently sent the couple some evil eye bracelets.
MailOnline has contacted representatives for Gigi Hadid and Zayn Malik for comment.
George's bracelets comes after Gigi confirmed her pregnancy while on Jimmy Fallon last week.
'Thank you so much,' she said after Jimmy congratulated her on the pregnancy.
'Obviously we wish we could have announced it on our own terms, but we're very excited and happy and grateful for everyone's well wishes and support.'
A father of two, Jimmy advised Gigi to savor the moment.
Gigi was appreciative she was able to fully experience her pregnancy, now that she's forced to stay indoors due to quarantine.
Gigi and Zayn are rumored to be expecting a baby girl.
Despite the happy news, it's been a rocky four-year relationship for the couple, who have been known to be on-and-off.
The pair reconciled in December last year after a year long split, during which time she briefly dated former Bachelorette contestant Tyler Cameron.
Gigi and Zayn started dating in 2015 after meeting on the set of his music video for Pillow Talk.
© Associated Newspapers Ltd.