How about I unintentionally make a friend feel fat?
That seems mean. Why do you want to make her feel fat?
Because she's very sensitive and it seemed like she didn't like me talking about her big ass
Even if it unintentional, you should avoid talking about her ass. You know it will make her feel bad and it will hurt her feelings. She won't want to spend time with you if it will lead to this.
I care about her feelings so I'm not going to mess with her ass to make her feel better.
Good I am glad. It is bad to hurt a friends feelings. Friends should be there for each other.