Miley Cyrus and Liam Hemsworth -- Overt Signs of Split

It's one thing not to be seen together, but when you unfollow someone on Twitter it's pretty clear ... Miley Cyrus and Liam Hemsworth are dunzo.

Miley 86'd Liam from the social media site yesterday. He's still following her, but it takes 2 to follow in a fiance sort of way.

Miley and Liam have barely been seen together in the last few months, and when they were they looked like they were in pain.

Was Liam pissed at Miley's twerking video? Was he upset with what she was wearing at the VMAs? Was he infuriated at what she did to Robin Thicke?

So much to be pissed over.

1:40 PM PT -- Adding more fuel to the fire ... Liam was spotted out last night in Vegas at the Mayweather fight sitting near "Twilight" star Ashley Greene.