The 'Hunger Games' actor has been dating the former 'Hannah Montana' star on and off for almost three years and while it was recently rumoured they were set to tie the knot, Chris says it's very unlikely as they're not ready.
The 'Thor' actor said: ''They're like 21 or something ... I can't see that happening. You have to ask him about his relationship.''
And it seems Liam, 22, agrees with his older brother as he recently said he was too young to wed 19-year-old Miley.
He said: ''Marriage and kids are way in the future for me. I'm young. It's not really on my mind at the moment - marriage, kids or anything.''
Miley sparked rumours she was engaged after she was spotted wearing a diamond ring on her wedding ring finger.
The singer-and-actress posted a picture of her manicure on twitter - revealing a big rock parked on her left hand in the process.
However, her representative denied it was an engagement ring.