You hate to think of yourself as a gay person. I grasp that. Your friend played a prank on you. Here is what I think happened:
Most parts of the body function in opposite pairs. Your mind likely functions with both attraction and repulsion like the opposite pairs of muscles in your body or like the sympathetic and the parasympathetic systems. You see a ball -- your mind thinks of it as part of you but also as not, two different points of view in tension. Its the same with other things, other people, ideas, places. Its the psychology of me/not me allowing you to function as an individual and to pull together all of your experiences into a single life story. To understand anything is to desire and to be repulsed, to connect with and to separate from. Hence that little peekaboo joke your friend played on you was a little disturbing. Its also why little kids love peekaboo when they are in development.
I think so because of some things I read about child development.