If you haven't heard this joke i shall tell it in an edit.
a young boy wakes up on his birthday and his dad asks him what he wants to do. boy: can we go t'fair? dad: go t'fair? you think i'm made of money? boy: but it's my birthday! dad: ok
dad: what do you want to do now? boy: can i have shot on t'roundabout? dad: shot on roundabout? i've already taken you t'fair! boy: but it's my birthday! dad: ok
dad: ok what now? boy: can I have ride on t'donkey? dad: ride on t'donkey? i've already taken you t'fair and given you shot on t'roundabout! boy: but it's my birthday! dad: ok
dad: what now then son? boy: can you buy me t'donkey? dad: buy you t'donkey? i've already taken you t'fair, given you shot on t'roundabout and ride on t'donkey! boy: but it's my birthday! dad: ok
dad: what's next? boy: can we call t'donkey wank? dad: call t'donkey wank? i've already taken you t'fair, given you shot on t'roundabout, ride on t'donkey and bought the donkey! boy: but it's my birthday! dad: ok
dad: now what? boy: can we tie t'donkey to roof of t'car and take it home? dad: tie t'donkey to roof of t'car? i've already taken you t'fair, given you shot on t'roundabout, ride on t'donkey, bought t'donkey and called t'donkey wank! boy: but it's my birthday! dad: ok
as they are driving along the donkey falls off the roof of the car but dad doesn't notice.