Is calling gay sex a sin homophobic?
Depends on the context.
For instance, if you are calling it a sin as an attempt to control what people do in their private life or justification for your foul behavior towards homosexual people, then yes, it is indeed homophobic. It is especially homophobic if you cherry-pick what is a sin or not, or which sin is okay and which is not. There are a lot of everyday behaviors that our sins according to the bible, but if you choose to harass homosexuals in particular, then it’s not because of your religion. At this point, it’s pure homophobia.
But if you are making a neutral common interpretation of the bible or a neutral observation of a common belief among certain religious groups, then no, it’s not homophobic. Most religions are homophobic, but you are free to choose to not let those religious beliefs impact other people, and you are free to choose to not let those religious beliefs be your own personal beliefs.
