Thank

I noticed yesterday that depending on who thanks me for what, I respond differently. Like when I was cooking lunch for me and the lils, mom thanked me because that's one less thing she had to do, and my response was "Yeah" like 'yeah, of course I'll cook for them' and then when Esme thanked me for cooking her lunch I said 'your welcome'. It's the same with any other time I do stuff for mom, like helping in the garden, helping clean, or even if I get her a lil treat from the store, when she thanks me I say "yeah" like its a basic thing I'm expected to do and doesn't need thanking. But when my siblings thank me for something, it's usually "your welcome", I guess I've built a hierarchy in my head without realizing. Mom is at the top, so she shouldn't thank me, and my siblings are my level or lower, so they should and they get varying responses based on that. Anyone else do that?