My mom dared me to date women from USA.

Since I was in grade school, everyone misconceived my timidness into being gay. When I reached college until I graduated, same things happened. I was used to being close with women since my siblings are all girls. My mother also thinks I'm gay because I've never introduced a girlfriend to her since then. But believe me, I'm not. I am in love with someone I can't call my own since I was a teenager up until now. I don't have to tell everyone the real score with my identity. I believe I shouldn't explain myself further because I don't have to. I'm man and I know from deep within that I am. However, my childish mom dared me to date women from USA before she believes I'm a real man. She was making fun of me, I guessed. I don't want to do it, alright. But how should I convince my mom I'm not gay without dating women from USA?