Panel 1
Chris's Diary: A super hero is never more vunerable than in the moments they are between identities.
Chris's sister: WTF

Panel 2
Chris: Hello sis, this isn't what it appears to be.

Panel 3
Chris: Please wait while I formulate my awesome lie.
Sister: MOM, Chris is watching porn!

Panel 4
Chris: Ewwww... but as long as you don't find out I am a super hero, PROBLEM SOLVED!