That is where the community needs to chime in and define what is acceptable.
Personally if you are asking if someone wouldn't have sex with someone on the other end of the political spectrum is asking for trouble and is a political discussion. The political question is front and center. If it ends up with fighting rather than a discussion it will only turn bad. Once fighting/argument happens we will begin to be just like the other communities with infighting, take for instance the current dustup on c/asklemmy over Rule 6. I've already left communities like this and will likely leave others as well. https://www.difference.wiki/argument-vs-discussion/
Asking for an opinion of someone asking to buy a drink is not. The political aspect is secondary and only comes about when someone has an issue with the act and feels it should be illegal, though it is generally accepted as not. This also segways into the legal aspect section. This is an English language community. In English speaking countries and culture we have a pretty standard set of national laws that deal with acts that are in an of themselves are considered illegal and immoral. That would be a great place to start. Adding the illegality statement also allows the community to self police and quickly identify issues on top of the instance wide rule.
I'm sure many of us recognize wikipedia as a place with the knowledge to help identify the majority in a situation. For same sex and sodomy we can begin here. https://en.wikipedia.org/wiki/Sodomy_law#Countries_where_same-sex_sexual_activity_is_illegal
https://en.wikipedia.org/wiki/Category:Human_rights_abuses is probably a category that will deal with most if not all NSFW cases outside of the political aspect.