What should i do? This is maybe a simple problem but its bothering me. Im always drinking coffee and usually will buy my grounded coffee and milk regularly. I will make it at home every morning. The thing is, my sister now without acknowledging me, will make her coffee using mine and use the milk more than what i would usually use. Its been a few days. Im still a student, and these things cost me a lot. It sadden me that she doesn’t even feel sorry or at least tell me she's using my coffee. Worse thing today i bought new milk box, and tonight after jog i found out it only left like a quarter coz she already pre made her coffee using tons of milk and store in fridge for her work tomorrow. I dont know how to properly talk to her about this mainly coz she’s the one paying my car loan and would give me 50 bucks every month. I totally feel suck and trying to just let it go coz i don’t to be such a bad brother. Maybe im just overthinking or a really stingy bad brother. Sorry if anyone feel this is stupid and childish.