Response to sarcastic brother? ?

Flip it around. Just like they say women get aggro when they're on their period, they say guys gett aggro when they haven't had sex recently. So laughingly say back something sarcastic like, "Rahr(like the noise an angry cat makes), do you need to go unload your gun?," "unload your gun" referring to him needing to go jerk off, or, "Rahr, it's really been a while since you got any, huh?" Not only are you attacking his manliness by suggesting he's being pissy because of being sexually frustrated because he can't get laid, but also making the cat sound will also attack his masculinity because it's basically accusing him of being catty. Doing it laughingly, even if fake laughingly, further diminishes him, because studies have shown that while the number one thing women are afraid of about men is them killing them, the number one thing men are afraid of about women is being laughed at by them, and it preemptively blocks him from saying anything about your period because you're not being pissy or angry but are laughing. Nothing really gets under a guy's skin than getting laughed at by a woman, anyone woman, even his sister, so if you're mad at a guy and want to get back at him, whatever cutting or sarcastic words you say, make sure you say them not in an angry tone but while laughing at him.

I'd say, "No. You basically irritate me 24/7."

Or, "No, bcuz if I were, you'd be dead by now."

Why do you want to escalate a situation with your brother when you both have to share the same house. Wouldn’t it be better to just ignore him? That way you can be the bigger person. Women who tend to always want to challenge men create a reputation for themselves, that is how the expression Karen was invented.