According to OK magazine, the pair called it quits because they are undecided over when to have kids.
'He wants kids and doesn't want to keep putting it off but it's not quite the timeline Miley had in mind... he is left heartbroken,' the source said.
'Miley put off plans for the wedding and Liam was growing tired of it... They haven't been getting along in recent months.'
COME ON GUYS, the world needs you. Your endless list of animal babies need you.
This could be why Miley recently went rogue and deleted everything from her Instagram page. But we really hope that's to do with an upcoming album/tour/launch of clothing line (a girl can dream).
The couple were previously engaged in 2012 but broke it off the following year, before rekindling again in 2016 and have been going strong since then.
Miley and Liam are yet to comment on the break-up so it's not officially a done deal yet.
And if you need a reminder that love is real, look no further than Liam's brother Chris and his beautiful birthday Instagram post to his wife Elsa Pataky. The man learnt how to salsa for her - that's love.