Deselect

<select id="multiselect" multiple="multiple">
    <option selected>Item1</option>
    <option>Item2</option>
</select>
<script>
$("#multiselect").kendoMultiSelect({
  deselect: function(e) {
    var dataItem = e.dataItem;
    var item = e.item;
    // Use the deselected data item or jQuery item
  }
});
</script>

<select id="multiselect" multiple="multiple">
    <option selected>Item1</option>
    <option>Item2</option>
</select>
<script>
function multiselect_deselect(e) {
    var dataItem = e.dataItem;
    var item = e.item;
    // Use the deselected data item or jQuery item
}
$("#multiselect").kendoMultiSelect();
var multiselect = $("#multiselect").data("kendoMultiSelect");
multiselect.bind("deselect", multiselect_deselect);
</script>

<select id="multiselect" multiple="multiple">
    <option selected>Item1</option>
    <option>Item2</option>
</select>
<script>
$("#multiselect").kendoMultiSelect({
  deselect: function(e) {
    // Call preventDefault() to prevent the deselection
    e.preventDefault();
  }
});
</script>