Gigi Hadid's sister thinks Zayn Malik should propose.

Zayn Malik and Gigi Hadid

Zayn Malik and Gigi Hadid

Although the 23-year-old singer has only been dating model Gigi, 21, for seven months, her younger sibling Bella, 19, believes the pair should tie the knot.

A source told the Sunday Mirror: "Bella's been joking with Zayn that he's being slow and drawn out, and needs to looks after her big sister as she's one of the world's highest-paid models and has taken his career to new heights of cool. She gets on really well with Zayn and has told him she'd love him as a brother in law."

However, Zayn is likely to be reluctant to rush into another engagement after his relationship with former fiancée Perrie Edwards ended last year.

Zayn reportedly dumped Perrie via text after four years together but later penned the single 'It's You' about the 'Black Magic' hitmaker.

He said at the time: "I just felt like I needed to put myself out there on that just because it was a form of therapy for me and it did help get me through some s**t."

Zayn and Gigi split briefly earlier this year but it wasn't long before they reconciled and they are now closer than ever.

An insider previously said: "Things are back to normal with them.

"They got through a rough patch that Zayn was facing personally and it started to put a dark cloud on their relationship. Gigi was there for him when he needed her the most and that brought them closer than ever."

Gigi supported Zayn after he went public with his anxiety issues, and a source said: "[Zayn] opened up to Gigi about his anxiety. [They] have been through a lot these past few months, but they are really trying to communicate better going forward.

"Zayn really appreciates Gigi even more after this because he sees how much Gigi is there for him."