you know I don't know Glenelg so this may be bit cheeky but when I seen this I thought of him is that naughty of me 

Just  wondering why he would need 2 chairs !!

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO. WAY 

That would be very handy for Dave 

The two chairs are so he can change sides so people will think he hasn't been sitting there all day in the one spot 

Dave's doctor told him he had to stop drinking a cask a day and only have a glass a day.  That presents a win win situation for Dave and his doctor