Their relationship started a long time ago, and it was full of turbulence, but now they are all fine and happy together, supporting each other.
The two started dating in 2009, when they first met on the set of the movie The Last Song (2010).
But they were officially together in 2010, when they showed on an Oscars event together.
Cyrus even used Liam as her muse for Can't Be Tamed.
Unfortunately in 2010 they have broke up for the first time, and after a couple of rough months being separated, the two were together again.
After some speculations about Mily's infidelity the couple went on a break, but in the same year (2013) they were spotted holding hands and kissing.
Since then, they had some troubled times (and breakups) but now they are together again, happier than ever.
They have even showed up together on the 90th Academy Awards red carpet event. Find out all about it, and click on the video above!