That is advanced linguistic humor. It assumes the listener knows Japanese well enough to recognize the errors.
The middle part is ambiguous – likely 身に , 見に , or a typo for こんな . uchi no otouto maji de dekain dakedo mi ni kona free
The series relies on "gap moe"—the contrast between the brother's intimidating size and his actual personality—alongside the comedic tension of living in close quarters. Why Fans Search for "Free" Access That is advanced linguistic humor
Use when you want to say: “Someone close to me is objectively attractive, but I have zero romantic/sexual interest, so others can appreciate them freely.” but I have zero romantic/sexual interest