Lance shared photos of B meeting the 20-month-old twins, Violet Betty and Alexander James, on Twitter Monday.
“I’m a new auntie for Lance’s babies !!! They are absolutely gorgeous babies !!!” Spears wrote on Twitter.
As seen in both of the sweet snapshots, Spears happily smiled as she held each twin in her arms while Bass, 44, carried the respective other. The singer’s husband Sam Asghari was also pictured standing next to his wife.