If you want to appear as straight, pretend you are really tired or half brain-dead. That's the key! When you talk, do slow slowly and in a deep, casual tone. Act as if you could care less about what you're saying. Be mindful of how you enunciate words, but if your voice isn't naturally too feminine you can learn not to give yourself away by just acting like a chill bro who's mixed antihistamines with alcohol.

Let ur KWEEN out sis.

This is how I mask myself when talking to straight guys.

But yeah, be yourself honestly. You're in uni, who cares what people might assume about you.

Can't escape that gaydar, huh?

Honestly, don't imprison yourself to false standards. Be yourself, please. If you're gay then embrace it, it's fine. People face discrimination all the time, you just gotta live your life according to your agenda. Phobia of all kinds will always exist, you can't succumb to it. Honestly, put it in reverse and think. What if someone were to say "ewww, you're straight that's nasty" wouldn't that sound incredibly odd and stupid to you? It's the same as someone saying "ew you're gay"....how is someone's personal preference nasty? It's a matter of people being afraid of something they don't understand. You can't control it. Be yourself dude, don't live under false pretenses.