The happy couple arrived at St Martin-in-the-Fields church in London to attend a memorial service to mark the 25th anniversary of Stephen Lawrence's death.
Grasping each other's hands, the pair stopped outside to speak with the murdered teenager's mother Doreen Lawrence, and her son Stuart.
While the couple weren't asked about the royal baby, their beaming smiles and loved-up appearance presume the soon-to-be newlyweds are ecstatic over the news.
The engaged couple are due to tie the knot in St George's Chapel at Windsor Castle on May 19.
The Duchess of Cambridge is expected to be attending but, with her baby son only a few weeks' old, she is not likely to stay for the entire celebration.
Prince George and Princess Charlotte are tipped to be page boy and bridesmaid at the ceremony in St George's Chapel.
For more news about the new royal baby, see here.