Really, really often.

I blinked. Everything looked the way it should as far as I could tell. "What did you do?" I asked. Strange, my voice sounded oddly high-pitched. Karyn just grinned. "Oh, nothing much..." She looked a bit taller than she should. I frowned. The way she was looking at me... I looked down. "Oh. My. God." I was a girl! An incredibly sexy girl too! I actually felt myself get a bit turned on just looking at me. Karyn laughed. "Believe me now, Jon-girl?" "Uh, yeah," I mumbled. "Change me back?" She shook her head. "It doesn't really work like that. But don't worry, it should only last a few hours. In the mean time, you can get to know your feminine side." "Or," I suggested, "I could go back to sleep and wait for it to end." "Oh, come on," Karyn whined. "How often do you get to be female?" "Too often," I grumbled. I slipped back under the covers, trying not to think about how different everything felt. "Okay," she said, "Let's make this more interesting for you: a bet." That caught my attention. "What *kind* of bet?" "Thumb wrestling. If I win, you go along with everything I say until the spell ends." "Fine," I agreed. "But if I win, you have to do everything *I* say." She nodded, and the thumb duel began.