A boy wearing a shirt with the Simpsons character, Ralph Wiggum, plays a Nintendo DS with his sister.
A boy is playing a Nintendo DS with his sister who he loves.
You can not infer he loves his sister.
We have no idea if he loves is sister. Who can say that, he might be mad at her or a number of things.
Just because a boy wearing a shirt with the Simpsons character, Ralph Wiggum, plays a Nintendo DS with his sister does not mean he loves his sister.