For a moment, Alex feels a sensation akin to a slap. He feels ashamed, and forgets to breathe. It takes him a moment. The realization. He feels like he betrayed him in that moment.

"I'm sorry I didn't tell you, then," he says in a rush. "I wasn't going to hide it from you. I just wanted to wait until your fever broke, and you felt more up to moving around, and--"

And it doesn't change the facts. Alex realized what happened and still continued to have sex with Neil, in a way. Just like that-- "I'm sorry. I'm shit. I should have told you then."