So, interesting thing, I have my first straight head cannon of an Etrian Odyssey character in my new Etrian Odyssey V guild, Guild Ice Bat. My celestrian shaman is straight, but he's also trans, cuz full cisgender AND heterosexual head cannons are for suckers. Jk if you your guildies are cis/het you are valid.
He's a massive dude bro ladies man, who hits on every woman he comes across (except for the celestrain who works at the bar, who's name escapes me, but her weird balloon boobs make him uncomfortable), and who's guild mates only tolerate him on their team cuz of his dank elemental buffs, and only tolerate him as a friend cuz he always knows where a party is going on, the best clubs in Iorys, and is surprisingly sensitive to his friends emotional needs and is a good friend to lean on when upset.
He also knows the best Botanist with the dankest herbs. (The botanist in Guild Venomfly V)