As a teenager, I did it "inadvertently". Ya see, I had allowed a few terrible experiences with girls to shape how I perceived myself sexually. I basically drilled it into my own head that no female would ever find me attractive, leading to repression. (Which was pretty stupid as I'm a moderately attractive guy, but I had other issues compounding this.) Anyways... Senior year, a girl in my drama class asked me to prom. I was completely caught off guard and panicked. Not only did I say no, I immediately doubled down and angrily accused her of trying to make me her charity case. I think I did that, in front the entire class mind you, to cover up exactly how absolutely confused and sort of terrified I was at the prospect of positive female attention.