President Biden and his family attended Nantucket’s annual Christmas tree lighting festival Friday after celebrating Thanksgiving at a billionaire pal’s secluded island retreat.

The public event wasn’t on Biden’s public schedule, but first lady Jill Biden spilled the beans to Coast Guard members Thursday — just after a Nantucket man gave Biden’s motorcade a one-finger salute.

The first family was spotted singing along to holiday tunes including “Jingle Bells” and “Oh Christmas Tree” after a community countdown from 10 to light the tree, according to a pool report. 

The president greeted the town crier, who was outfitted in a top hat and coat with tails, before returning to billionaire David Rubenstein’s compound.

Earlier Friday, Biden announced a new travel ban on eight southern African countries due to a new and potentially more contagious variant of COVID-19 — before shopping Nantucket’s shops and greeting supporters.

The first family relaxed Friday after enjoying a holiday feast Thursday featuring thyme-roasted turkey, roasted vegetables, sweet potatoes and stuffing. Mashed potatoes didn’t make the menu.

For dessert, the Bidens had chocolate chip ice cream and a selection of apple, pumpkin and coconut cream pies, the White House said.

Biden visited the island off Cape Cod as his approval ratings are in collapse amid the highest inflation in 31 years, which has driven up the costs of everything from turkey dinners to gas.

A resurgence of COVID-19 nearly two years into the pandemic is sapping Biden’s former political strength — the perception that he’s effectively managing the coronavirus — and his net approval rating has consistently been negative since the end of August, when the Taliban’s reconquest of Afghanistan triggered a chaotic and bloody US troop withdrawal.

On Thursday, Biden’s approval hit the “single digits” when an island resident gave him the middle finger as he arrived at a Coast Guard station for a brief visit with sailors. Biden has received increasingly vulgar welcomes even in solidly Democratic states like New Jersey and Connecticut.

Nantucket’s weekly newspaper, The Inquirer and Mirror, reports that Biden as vice president also participated in the island’s tree lighting event.

“The president was a visible figure during his vice-presidential visits, shaking hands on Main Street during the annual tree-lighting and community caroling the day after Thanksgiving, shopping, biking, taking in a movie at the Dreamland Theater and even hitting the water at Children’s Beach as part of the Atheneum’s Cold Turkey Plunge fundraiser on Thanksgiving morning,” the newspaper reported.

Vice President Kamala Harris remained in DC for the long holiday weekend. Her husband Doug Emhoff, the first Jewish spouse of a president or vice president, will light the National Menorah near the White House on Sunday to kick off Hanukkah.