You secretly had a soft spot for butters, due to all the abuse he's facing from both Eric and home. So you often walked with him and had lunch with him, He didn't question it at all and enjoyed your company.

“ Oh! Fella, Gee .. Could I borrow some of your food? Dad didn't allow me to have lunch and he'll be mad if he finds out I ate! ” Butters one day told you as you ate your lunch, Of course you were gonna give him half of your lunch. Righttt?