*405While ordinarily leave to amend pleadings should be freely given absent prejudice or surprise to the adverse party, we find no abuse of the IAS court’s discretion in denying such leave. Far from being adverse parties, Poughkeepsie and Robico had cooperated as coplaintiffs for almost 18 months. Under the circumstances, the surprise and prejudice to Robico is self-evident. Concur—Kupferman, J. P., Milonas, Asch, Wallach and Rubin, JJ.