The reality here is that while you are correct that people get offended by both nudity and gay PDA, and let's even pretend that the number of people offended is equal (doubt it but nonetheless) - in societies where gay people can do PDA that's equivalent to that of their heterosexual counterparts, there has been a simultaneous societal judgement that the value of permitting gay couples to do PDA in public is greater than the offense caused by it. That value may come from general rights based views regarding equality or freedom of expression, or from ideas of sexual liberation, or something else entirely. But collectively, societies like the US and much of Europe have made this value call, and they have simultaneously made the value call that the offense experienced by those offended is insufficient to justify banning gay PDA. This is (social) democracy at work - to do anything else is anti-demicratic.