Strict tag filter?

I created a small external popup with custom menu to search via tags.

The url looks like this

Site.com/?category_name=Cool&Tag=tag1,tag2,tag3

My question is:
Lets say I have two posts in the same category that share 1 tag, but not others.

Post one tags:
Cool, stuff, amazing, five

Post two tags:
Cool, sweet, awesome, seven

Now two post share one tag, but I don’t want them to show up in the results unless all other search tags match.

So since post TWO did not have “sweet, amazing, five” it should not show up when I search for “Cool, stuff, amazing, five”

I don’t know if I am being clear lol I am horrible at trying to explain things.

http://wordpress.org/extend/plugins/cat-tag-filter-widget/