Alternate response for panel five: "The same way Susan was able to read comments during lunch?" Except that's not what happened. She heard it from Rhoda. SO THERE.
Wait a minute... Grace! Do you know who Catalina's secret girlfriend is?! But how could you possibly know, unless.. O. M. G. It's YOU, isn't it?! HOW COULD YOU?!
I suspect Justin's extremely anime thought representation in the first panel is in part the result of me recently making a Pokemon fan comic with similar expressions. It's certainly more chibi than when Susan flailed her arms.