That metaphor is a great one--as much as it hurt for them to have that fight, it was also just as heartbreaking to see them go from there to sex. It's a sign that there is trust there, even if they are on very different sides of any issue.

I can see that Charles does stand up for him self, but I think this was the first time it took a position that make Erik fight back to press the point. They are always fighting and Erik just deflates at a point, but he couldn't do that here and I like that finally happened if only to see Erik that there is more to Charles than just the man he loves and the one who's the pie-in-the-sky academic.