ShowHide module duplicate when edit again

I find that the show hide module will duplicate once i open the edit view, the showhide source code changes to:

{{showhide id="1" showmessage="Show" hidemessage="Hide" effect="appear" effectduration="0.5" style="background-color: #ccc"}}Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible{{/showhide}}

(% style="background-color: #ccc" %)
(((
(% class="showhidebutton" %)
(((
html
<a href="javascript:void(0)" id="showhidebuttontext1" data-show-duration="500.0" data-show-effect="fadeToggle" data-show-message="Show" data-hide-message="Hide">Show</a>
/html
)))

(% class="showhidecontent" id="showhidecontent1" style="display: none;" %)
(((
(((
Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible
)))
)))
)))

(% style="background-color: #ccc" %)
(((
(% class="showhidebutton" %)
(((
html
<a href="javascript:void(0)" id="showhidebuttontext1" data-show-duration="500.0" data-show-effect="fadeToggle" data-show-message="Show" data-hide-message="Hide">Show</a>
/html
)))

(% class="showhidecontent" id="showhidecontent1" style="display: none;" %)
(((
(((
Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible
Here is some hidden content that can become visible
)))
)))
)))