He literally says that he is gay...if you choose to write the paper on gay rights, he pretty much says, "I'm gay so why not write about something I know about" or something to that effect lmao
On day 1 Zoe also straight up ask you if you’re gay if you accept Aiden’s invitation, and Mason says he is; if you hang out at the library with Jude you also say you are.
The only day 1 option that I don’t think says it explicitly is hanging out with Quinn at the library, I think the most you say is that Jude is “a pretty attractive guy”.