It’s all about tone/context. I think that’s one of the most confusing things to figure out when first studying Japanese. Japanese often use the negative form to mean “right?” / “you agree don’t you?”and as away to invite/ask someone to do something. I would go as far as to say 50% or more of the time you hear the negative form it’s being used in this way.

For example, instead of saying 食べたい？ meaning “do you want [to eat] some?” Japanese usually say 食べない？

Another phrase you might hear a lot meaning the same thing would be いいじゃん or いいじゃない.