Answer - when it is the 'Barcelona' bench from B&Q

http://www.diy.com/diy/jsp/bq/produc...ODID=8 070063


Bought one of these at the weekend and erected it, only to discover
that it is designed to support 100kg or 16 stone.

Now pardon me for being stupid, but what on earth is the point of that?
Surely two people are going to want to sit on this at the same time,
but two adults, or me and my 4 year old, would be too heavy and risk
collapsing it!

At no point on the packaging or the web site does it say - WILL NOT
SUPPORT TWO PEOPLE

I am loath to take the thing apart and go get a refund, but this is
probably what I'll have to do, otherwise everytime my inlaws or parents
are round and two of them try to sit on it I'll have to tell them not
to!

This is preposterous.