She was angry - not at him, he got that. But he felt like she was punishing him for it.
"It's not that I don't care." He cared. He cared a lot. He was a god but he had feelings and he could be hurt; physically, emotionally, mentally. No one liked feeling manipulated and no one wanted to get hurt and Ares was no different.
"I can live with it. I can look past it. We all make mistakes and we all hurt others, especially the ones we are close to, sometimes without knowing it. We're not all perfect but we're not all going at each other's throats trying to tear everyone else down."
He genuinely believed that Aphrodite hadn't done what she did to hurt him. It just happened as a result of wanting to expose Hades for whatever it was.
Who knows? Ares might have done the same thing in her shoes.
"We've all wronged each other before at some point. I just... I don't want to have to choose between the two of you."