Our boy is toilet trained but he started the other day weeing on our bed. At the time i thought it was a pure accident and led him straight outside but i think its a behaviour thing as he's done it twice more!

Any suggestions on getting him out of this awful habit would be appreciated!

He is 9 months and an entire male

The quick way of stopping it is to keep the bedroom door shut while you're finding out the reason behind it. :) Has there been any change in your household routine lately?

No changes that i can think off not even small ones!:rolleyes:

This is a teenage dominance issue. He knows this is your 'den' and he is leaving his mark on it.  As JG suggested, keep the door closed and he will grow out of it.