I had been working on the assumption that the translators were two-way; that is, Peter's would turn all languages into English for him, but also turn his English into whatever language the listener needed it to be. Apparently that's not the case! Word of God. So, this:

It's okay though, he liked it.
But now I wonder if my way makes more sense. How are the Guardians going to speak to the Avengers when they meet? Nobody on Earth has a translator implant.