Why did my female friend call me dad?

I've known this girl for almost 7 years, and I just recently (a month or so ago) confessed that I had feelings for her. I can tell she is definitely playing hard to get, but sometimes she shows affection, even though she has turned me down twice. Just the other day, however, i got her to cuddle with me, which is when she called me dad. She immediately began freaking out, and it took me a while to calm her down. Now she denies that she said it. WT F? Is there some subconscious reason for this? Any information would be helpful!