He's Ferb Fletcher. Staying calm no matter the circumstances is such a part of his character that having him NOT be calm in your story (no matter how justified the reason) is potentially flame bait. Same with Phineas not being happy-go-lucky. Honestly; they're human which means they have more than one setting. Still funny how he manages it here though. He loves his girls but this he does NOT.
He and Phineas technically tie for me; if I had lived in Danville when I was a kid, I'd have been part of the Summer Vacation Gang no question! Though if someone looked over my P&F fanfic ideas, they'd probably conclude Phineas is my favorite because I'm SO directly mean to him (it's just too easy to be mean to him; I know I'm not the only one)!
This is Me my Mom and my Sister when my dad gets home. One time we were all arguing and I saw him walk in then walk out like, "Nope. Not dealing with this..." It pissed us all off but I'm only now finding it funny... I feel so bad for all the crap we put my Dad though when were all moody. XD