Pictures of the 48-year-old rocker with his arm around two bikini-clad teenagers in St Tropez were posted on the popular social site complete with diary details.
Bono was on vacation with long-time friend Simon Carmody, a musician and former member of Irish band Golden Horde.
The Irishmen met up with two 19-year-olds, American fashion student Andrea Feick and her British friend Hannah Emerson.
Feick said their relationship had never crossed the line beyond friendship. "For somebody who's much older than I am ... no thank you," she said.
The images show Bono wearing his trademark hat and sunglasses while drinking with the two girls at the Nikki Beach bar in St Tropez.
Later that evening, they took a stroll along the beach, then made their way to a luxury yacht, thought to be the Cyan, a $12 million, 140ft yacht with six cabins owned by U2 guitarist The Edge.
Bono, Carmody and the girls partied into the night on the yacht.
Bono's 26-year marriage to wife Ali is famously strong.