For during his unexpected eight-month stay at the Maidment family home in Goughs Lane, he's also been nipping back to his real home round the corner for a midnight snack.
"I was putting a bowl of food out every other night for him while he was gone and it was always empty the next morning," said owner Jane Batt.
"I never saw him but I felt a sense of relief knowing that he was all right."
Jane was reunited with Billy - real name Decker - last week after Diane Maidment had told the Knutsford Guardian how he needed a new home because her own cat, Henry, could no longer stand the sight of him.
Decker had disappeared last summer.
At first Jane assumed he had gone on one of his usual three-week excursions.
But when he did not return within a couple of months she started to think he had gone for good.
"He goes off on a little holiday for a few weeks usually in June," said the mum of two. "But in the past he had always come back."
But a plate of pink salmon made Jane suspect that maybe Decker hadn't gone far after all.
"I put the salmon out in the garden about two weeks after he had gone," she said. "I saw Decker run straight for it but then he left again when the plate was empty. That was the last we saw of him."
Since he returned home to Astley Close on Wednesday evening, life has not been quite the same in the Batt household.
For Decker has changed.
"Peaches, our other cat, used to sit on him when he was in his basket until he moved," said Jane. "But now he hisses at her."
He has also been sneaking back to the Maidment home for a spot of tea.
"He obviously liked having two homes," said Jane.
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