dd2 (aged 8yrs 7months): "Mum, listen to this joke!"
me (excited): "Ooh go on then..."
dd2: "What do you call a deer with no eyes?"
me (genuinely excited/eagerly awaiting punchline): "I don't know, what do you call a deer with no eyes?"
dd2: "Eye don't know!" 
I know it's not PC but dd1 and myself were literally streaming with tears and shuddering in order to stifle the laughter.
Oh how I LOVE that girl 