One time (before I even realized I was bisexual) I asked another guy how big his dick was in front of a bunch of people. They all laughed at me. Do you think anyone suspected I was gay or bisexual after me saying that?
I don't think so. I know for girls we talk about stuff like that all the time (like boobs and vaginas though), but I know for men things are different. I wouldn't worry too much about it, I know that I stress about stuff and become paranoid over things people forget in an hour.
Nah dude, straight friends have asked me that like 10 times in middle and high school. Guys are just curious about sizes so they can know if theirs is big or not. Whether their gay or straight has nothing to do with it.
I did this once during my first few days of college. (Same situation: didn't know I was bi yet) Got some weird looks, but I never really saw they guy on campus after that so I didn't have anything to worry about. Encountered him once more after that in my senior year. He was working at a desk at the student center, and oddly, I recognized him. Never thought I'd remember some random guy whose package I asked about three years prior, but the memory suddenly flooded back in the middle of him helping me out with something. Luckily, he didn't seem to recognize me.
We probably all drop hints by accident. Sometimes when I'm talking to my male gay colleague I literally see him thinking "that's so gay" lol (he knows). But I don't think straight people notice this, they think everyone is straight like them unless they have good reason to think otherwise.