Alighting Puns

This guy comes in all the time; he's a bit older, i'd wager around 70 or so, and he's always wearing these awesome bolo ties with sick button-down-shirts that have turtle patterns on them. None of this is relevant to the joke but i feel it necessary to at least give a bit of background.

Any way, he comes in, orders his pictures and when he came back to pick them up, he goes: "Hey, did I tell you what the hat said to the hat rack?" "Whaaa?" " 'Alight, you stay here, I'll go on a head' "