Is it normal to get aroused when a girl says thank you?

I was playing an online competitive game with a girl who I am friends with on the website. She is from Ukraine and I am from America. She always loses to me in this game but our games are always very close and she always sends me a rematch. Anyway, she made a huge mistake in one of our games and I was basically about to win. But I felt bad because we were having a great game and I was only going to won because she made the obvious mistake. I know she is good at the game and would never make a mistake like that under normal circumstances, so I thought maybe she was in a rush that day. I offered her the option of canceling the game and she accepted immediately. Then she sent me a rematch again (as usual) and she wrote in the chat box "thank you" with a little smiley face. This really turned me on and I was surprised because I didn't expect it to. I sent her a message saying that I don't enjoy winning games where my opponent makes an obvious mistake, and then she replied "me too! i will try not to do it again" with a smiley face. I've just been thinking about her a lot.