From Justin Bieber and Selena Gomez to Gigi Hadid and Zayn Malik, meet the celebrity boomerang couples who just can't stay away

We take a look at the ups, the downs — and how long we think they'll last. Justin Bieber, 24, & Selena Gomez, 25 Since…

Read More From Justin Bieber and Selena Gomez to Gigi Hadid and Zayn Malik, meet the celebrity boomerang couples who just can't stay away