Not only is Marty ramping up the tude, she's also getting... pretty callous? The descriptive phrase "big, bad" is usually reserved for sarcastic contrast (like the big bad hangnail I had last week), but brain tumors are obviously pretty serious, so I find this confusing. Your tude is confusing me, Marty!
Luckily it's not phasing Lu Ann in the least. Calling your dad a loser? Using his first name? The revelation that you know we've been feeding you a pack of lies, dirty rotten lies?? Yeah, well! Stuff happens. Come back to squiggle art!