You can use ClusterItem.ClusterState with the ClusterItem.HideExpanded property. When the ClusterState is Expanded then the ClusterItem shows its items. Also when at the same moment you set the HideExpanded to 'true' then the Cluster will be hidden.
And you can use the ClusteredDataSource.Collapse method to hide the cluster's items.
For more information please take a look at the following documentation topic:
I have attached a sample solution which shows cluster's items by right mouse button click and it shows cluster again by left mouse button click on any item of cluster. I hope it helps.
the Telerik team