Prince William sparked royal baby rumours in Cambridge on Wednesday after accepting a romper suit from a well-wisher, telling her "I'll keep that."
The Duke of Cambridge was in the city with his wife Kate when he was presented with the gift by Samantha Hill.
The handmade baby-gro featured a helicopter and the words "Daddy's little co-pilot" - a reference to the Prince's career as a search and rescue captain.
'I'll keep that': Prince William was given a baby-gro during a visit to Cambridge
"When I gave it to him he said 'I'll keep that' and handed it to his aide."
The royal couple received a rapturous welcome from hundreds of well-wishers who lined the streets of Cambridge to greet them on their first official joint visit to the city since their marriage.
Samantha Hill handmade the baby-gro 'for when his little one comes along'
Speaking at a reception in the university's Senate House, William said he and Kate had looked forward to visiting Cambridge ever since they adopted their titles on their wedding day in April last year.
"We both feel immense pride at being associated with Cambridge, a place renowned the world over for its dynamism, beauty and learning, and it is lovely for us to be here together today," he said.
William paid tribute to the work of Cambridge University, saying its academic record down the centuries left them both feeling "very humble".
"Within a mile of us, gravity and DNA were discovered," he said.
"Many of the brilliant minds who, through their later work at Bletchley Park, did so much to save our country and the free world, were given first flowering to their genius here at Cambridge.
"This university has more Nobel prize-winners to its name than all but a couple of countries."
On a more light-hearted note, William joked at his brother's expense about their visit to Trinity College, Cambridge, five years ago.
"My brother Harry and I were fortunate enough to come to Cambridge five years ago, when we spent a couple of days at Trinity," he said.
"I have to say, it's the closest Harry's ever got to university."