Why do people think that UGGS on GUYS are gay?

I remember I was watching a show, The Real Housewifes of New Jersey, and the girl was meeting this guy who always was wearing girl clothes. And she said hes not gay he just likes to wear girl clothes. I obviously thought that was weird but hey everybody has there own opinion and see there are people out there that agree with you. UGGs are supposed to be used for girls but if guys wanted to wear them they can go ahead. HEY! Its a free country. LOL!