It is generally accepted that clusters of hydrophobic moieties in water fall apart when urea is added in substantial amounts. We performed atomistic molecular dynamics simulations of hydrophobic solute pairs and found evidence that urea molecules act as "glue" bridging these pairs thereby holding them together. The picture is quite general as it applies to aliphatic-aliphatic as well as aromatic-aromatic interactions. The implications of this finding on the role of urea as a protein denaturant are discussed.