Y'know the last cat I had wasn't even my cat,
  he was the neighbour's cat
Yea! He defected... came over to our house
My neighbours they had a holiday home down the country
  and used visit it often on the weekends
So the poor cat would be left behind at home
  and he'd get lonely
So he'd come out to us, and he liked us so
  much
We used give him a great reception
He'd get so much love and attention, nice
  food as well
That he decided to stay with us rather than
  go back home
We even bought him one of those nice furry
  little cathouse bed type things
Put it out in the garage and he'd sleep there.

But whose cat was he now then, was he ours
  or was he still theirs
Did they still have a claim on him
Or was it up to him to choose,
You know it could have caused a
  Constitutional Crisis
Could have gone to Court
Who had ownership of the cat
Could have been a real tug of love affair
A bit like that film what's it's name...Kramer
  vs Kramer
Luckily the neighbours though they didn't
  seem to mind that much.

Of course, the punchline to all this was, one day my Dad was out visiting
  my neighbours next door
When who should he see lying there on the sofa looking very contented
  and very much at home
Yea! You guessed it.

Are you thinking what I'm thinking
Yea exactly! I bet the cat...our cat the Defector
He was probably a Double Agent all along.