Who's On Top?

I used to think that only men could be on top. Then I had a girlfriend who like to be on top. At first I thought it was weird and I kind of laughed about it.

Then I realized I liked it. Now I find it difficult to be on top. I try really hard to be on top to please the girl but it just doesn't feel natural. I'm not sure why it happened but no matter how hard I try I can't seem to change back to being on top!