Well, to be honest, I think it's sorta cool.
But I also think it would only fit well with certain personalities. For instance, one type of person might love the name and play it up ("Nice to meet you, I'm Peter Danger!"), while another might be embarrassed by it.
If your husband won't bend, you could consider two middle names -- maybe even two middles that start with the same letter (e.g. Peter Daniel Danger Lastname) so that your son can use a middle initial freely (and have the option to give either one name or the other if someone asks, depending on who that "someone" is).