Venn Diagram

I have lost you to sleep again
 Sleeping as we do on opposite sides of a Venn diagram
 I read the time in shadows on your wall
 The shards of light through the slats on your window
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 I ease myself from under your languid arm
 I fumble on my boots and hear you breathe through your alarm
 And I disarm it for you, you rarely heed it anyway
 I wouldn't want it to intrude upon your dream
 School bell ring, messing up the play
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 A note, penned clumsily in this century's type-ruined hand
 Saying, "Gone down the shops for a walk
 I'll bring back some sandwiches"
 And then I kiss your face, the black and the blue
 I tie it into my laces, I don't want the wander blocking up the view
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 I stumble out into the afternoon
 I'm still salty from drink and the late night pool
 And I'll be gone an hour at most
 And you will be more diagonal
 And I've a head on me in the post
 I know, a castle swallowed in the swell