When someone can't take a joke properly or appears to clingy. Can be referred to just about anything in any situation.
Person 1: I told her we were going to have this massive orgy and she believed me.
Person 2: Wow, what a clingon
Person 1: She doesn't leave me alone
Person: She's such a clingon
Person 1: Omg he doesn't text me back quick enough
Person 2; Stop being a clingon
Person 1: I was acting pissed off and she thought I was serious
Person2: We all know she's a clingon
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