She's not letting heartache slow her down.

Gigi Hadid hopped a flight to Paris out of LAX yesterday, and the supermodel looked every inch the chic traveler in a tan sweatsuit and jean jacket. We still can't believe she and Zayn Malik are dunzo, but it sounds like it's unlikely they'll get back together.

So what was the real reason the British heartthrob and the catwalker called it quits?

"Zayn was always more introverted than socialite Gigi, who had a wide circle of friends and loved being out on the showbiz scene. He didn’t get on that well with her showbiz friends and that become a bone of contention," a source told Closer magazine.

"Zayn was the one to end things following a string of heated rows, leaving her heartbroken - even though she knew, deep down, it was the right decision," the source added.

Rumor has it she has been secretly exchanging flirty texts with Lewis Hamilton, but we've yet to see any evidence that they're actually hooking up!