I'm actually quite flamboyant (to the point of being gay) on the internet, but in real life I don't think that shit flies. I'll try to gradually change, but I've been like this for as long as anyone has known me (in real life). A sudden change would seem fake.
I've actually had a chat with this girl in the past. It was just the two of us so I didn't feel the need to put on an act. This led to her questioning my sexuality, which was something I expected but I told her it was just a joke.
There is only one thing I can think of that would warrant some sort of mistrust. She once asked me t tell her as soon as I ever met a girl I liked. She was the one who I liked at the time but I couldn't really tell her because I didn't think it was appropriate nor did I think it would ever happen. This was back in the 7th grade and hopefully she has forgotten and hates me for some other reason.