This paper describes a new technique for allowing multiple users to haptically interact with a set of deformable slowly-simulated objects in a stable manner. Stability has been approached in the past by various researchers using passivity theory in order to avoid having to model the human operator closing the haptic loop. None of these solutions however can work well without the use of high update rates and thus break down in the case of haptic interaction with slowly simulated virtual environments such as the ones featuring highly precise deformable objects. This is particularly true for the case of surgical simulation with force feedback, where precision is a key issue and where complexity can reach high levels. The techniques presented in this paper are based on the concepts of local model for haptic interaction adapted to deformable objects. Such approach allows multiple users to stably interact with a same object while feeling the influence of other users on the same object. Experimental results employing a PHANTOM haptic interface are proposed for a simple example.