What does "better you than me" mean in this context?

Question

Harry felt restless. He wanted Quidditch Through the Ages back, to take his mind off his nerves about tomorrow. Why should he be afraid of Snape? Getting up, he told Ron and Hermione he was going to ask Snape if he could have it.

"Better you than me," they said together, but Harry had an idea that Snape wouldn't refuse if there were other teachers listening.

I searched it on the web, but they say differently about the phrase.

The free dictionary says:

better you than me

set phrase I'm glad that I don't have to experience what you just mentioned having to do or go through. A: "My boss is making me come in this weekend to do an inventory of the entire store. It's going to take forever!" B: "Wow, better you than me. I'm going to a baseball game this weekend!"

But according to this site:

'Better you than me' basically means that I don't care about you( as long as it doesn't affect me)

There seems to be a slightly different interpretation for the phrase. The latter is more closed to the context I quoted here.

What's the correct way to understand the phrase?

Answer 1

According to the Cambridge Dictionary, the expression "better you than me" has this definition:

said by someone who does not want to do the thing that someone else is doing

This is a mainly US expression: the UK equivalent is "rather your than me". This fits with the first definition that you quote, but not the second. I agree with the Cambridge Dictionary and your first definition: I think that the second definition is wrong.

A better expression for the second definition would be "I'm alright Jack"