Peter tenses.

"She read the journal?" he repeats, slowly, uncomprehendingly.

And then the reality of his situation sinks in and his face flushes red. He really wants to crawl under a blanket right now, but they're both sitting on top of his comforter right now and the last thing he wants right now is for Liz to feel bad about that on top of everything else.

But still, his embarrassment is immediately apparent.