As you scroll through your texts you notice you don't have any from your girlfriend. All of your texts look the exact same as you left it in your home world, except that instead of her name, you find a guy in its place. He has the masculinized form of your girlfriend's name and shares her last name. If you didn't know better you'd say he was her twin brother.
As you look through your texts with him it becomes glaringly obvious. In this world your girlfriend is actually your boyfriend, but from the looks of things, it may not be much different. In the places on your phone where you used to find dirty pics she sent you, you instead find his, pussy and all. You start to feel a fluttering as you're turned on by naked pictures of a man that looks like a flat-chested, masculanized version of your girlfriend.
You've never been attracted to men, nothing against homosexuals, just wasn't your thing. But now looking at naked pics of your supposed boyfriend, you start to get turned on. And you instinctually start to grab at your penis, it starting to harden as you stroke up and down. You guess here you're gay, or still kinda sorta straight, you don't really know, and frankly don't care, because right now you're turned on by pics of your boyfriend's pussy.