My parents have asked me to sign their will along with my other siblings and I ididnt ask them why so what reasons could there possibly be?

To confirm you have read and agree to the terms to stop any potential unpleasantness after they are gone..

So everyone is aware of the terms, So one child can not try to hide the will perhaps and take things for themselves ( read some of the nightmares on this board people post)

You asked this under Bereavement. Please don't think that just because your parents are writing a will that it means they are dying. Anyone with money and property should have a will.

{Mod Note: Moved to appropriate forum <>}