"I was quite surprised how tolerant he was of people. It wasn't scared at all and seemed quite comfortable having people wandering around it 2m to 3m away."
Barry says the couple moved the outdoor furniture partly to block it from getting into their garden.
"When I moved the sofa into the shade, the seal hopped up. It made itself right at home. I stood there saying to Alison 'this thing is taking the p***."
The Gibsons didn't feed the animal and have only toyed with the idea of naming it - Cedric or Sammy - and were pleased when it moved off on its own once the couple settled in for a night of TV.
Seals are not an uncommon sight around residential homes and businesses in the Coromandel Peninsula suburb of Whitianga.
Emily McKeague from the DoC Whitianga office says seals are protected under the Marine Mammal Act and unless obviously injured or posing a threat to itself or to people, should be left to do their thing by giving them space to rest.
The DoC hotline 0800 DOC HOT is manned 24/7 for injured wildlife.