Okay, so my SO & i live with his family (his mom, aunt and little brother)

My fiances little brother is 19 (we'll call him C) and I turn 20 in Feb.

So we arent that far apart age wise obviously.

Anyways we have never really gotten along but I try and connect when I can so it's not so weird & awkward.

My fiance and his brother dont get a long at all. Recently C has been paying a lot of attention to me. What I do or dont do. What he sees me do and what he doesnt see me do.

EXAMPLES:

-C mentions when I do or dont drink a certain soda

-how many times I've read a certain book

-how many days ive worn the same shirt (I wash it if I know i am going to wear it multiple times a week as a lounge shirt)

-What dinners his mom makes that I do or dont eat

Idk if hes trying to connect with me or what. I think it's a little weird.

He comments on the above examples to me whenever my fiance or his parents arent around.

Is it weird or is it just me?

I've told my fiance every time C comments about something I do or dont do. And he just brushes it off and says "idk"

So I dont know what to think or do. Its harmless, it's just a bit weird and annoying?

Any advice?