First lady Jill Biden celebrates her 70th birthday with the president at their beach house in Delaware

• The Bidens celebrated the first lady's 70th birthday at their beach house in Delaware.
• They spent part of the afternoon biking together.
• The first couple is expected to return to the White House on Friday.

President Joe Biden took Thursday off to celebrate first lady Jill Biden's 70th birthday at their vacation home in Rehoboth Beach, Delaware.

The Bidens planned for a "quiet" day together in the beach town without family and friends, Michael LaRosa, the first lady's spokesperson said, according to the Associated Press. The first lady was already at the beach house when Biden arrived on Wednesday night, per the AP.

The first couple started their morning in "sunny and warm" 66-degree weather and spent part of the afternoon biking along the Gordons Pond Trail at Cape Henlopen State Park surrounded by Secret Service, the White House press pool reported. When asked if he enjoyed the ride, Biden responded to reporters: "Yes."

They are expected to return to the White House on Friday.

Biden purchased the beach house, which sits on a cul-de-sac, for $2.7 million in 2017 after his vice presidency, AP reported. The move came less than two years after the couple's son, Beau, died of brain cancer. A sign on the house reads "Beau's gift," while another sign says "Forever Jill," per AP. The Bidens have been married for nearly 44 years.

The mid-week trip marks Biden's first visit to the couple's beach house since he was inaugurated. The president has previously traveled to his home state, typically on the weekends, to stay at his longtime residence in Wilmington.

The first lady's milestone birthday comes after she recently completed teaching a virtual course at Northern Virginia Community College. The longtime English professor does not plan to teach over the summer, AP reported.