[Chaohinon]

There are a lot of other factors to consider. Have things such as your diet or your level of sexual confidence changed at all in the past year?

I think the most logical possibility is that as you've spent more and more time with your girlfriend, you've become more comfortable with sex, and thus your sex drive is stronger. So it's not so much that you've gotten bigger, but that you weren't meeting your "full" potential a year before.