Why is my ex trying to make me jealous?

well were not exes, but we dated for 3 monthes & de had feelings for each other. HE calles things off, & i was heartbroken. 24+ hours ago i decided to temporarily cease contact so i could ease my depression & sadness over the sitution. well he gave me his childhood teddybear that had alot of symbolic value., & he wants me to keep it still? He also makes flirty stats & talks abiut how he's "waiting for someones call". hes trying to make me jealous (he knows what bothers me), but HE called things offf? is this cause i'm playing things cool & not freaking out? I dont get itttt. Explain?