Protective Peter headcanons???
I'm gonna come at this from a kind of Spideytorch bend, if that's what you wanted, anon, but I think in general Peter protective instincts are rooted more in him as a person and less in the identity of his partner, so they're interchangeable.
"After what happened the other night with those muggers --" "You're worried that if you're not around to save me, I'll get hurt being all myself in this big, bad city. Honey, you're sweet. A male chauvinist, but sweet." (Marvel Graphic Novel #72: Fear Itself) I fully believe he'd be like this with a male partner, too, but get him, MJ.
So the thing with Peter Parker is that I'm always trying to root him in the physical. I think because he has a reputation first and foremost as a quippy smart guy, people tend to go towards verbal or intellectual traits, and he does embody those -- but Peter exists very firmly as a physical character. So when I'm writing him being protective, there's a very physical aspect to it. Putting himself between Johnny and a perceived threat, tugging Johnny behind him, having an awareness of Johnny's personal space -- intercepting a fan if they get too close, or just kind of safeguarding his personal space. With Johnny (and with all his canon partners and his close friends) there's an awareness in him that he's physically much sturdier than Johnny, especially when Johnny's flamed off. He can dish out a lot of physical damage, but he can also shrug it off. So I think he generally has this awareness where he's going to physically get in front of Johnny if he thinks there's going to be an altercation. (Depending on when you want to set things, Johnny having been previously beaten into a coma during Civil War is not going to help his instincts to physically put himself in front of him if he senses danger.) No one's going to touch Johnny on his watch.
There's also the suggestion in canon that he can tie his spider-sense into his partner's wellbeing, like when he's unconscious and wakes himself up because Mary Jane's panicking in Marvel Knights Spider-Man. Which is really interesting because then it becomes not only about physical threats, but also emotional ones, too. Something I've talked about before is how Peter is a fixer. He really, really likes being the fixer -- the person in his friends and family's lives that they rely on in times of crisis. If there's a situation happening that's upsetting Johnny, Peter's going to want to fix it. Johnny is absolutely not used to that, so I think there's a little bit of friction about it at first, too. It's not something he expects, and Peter can be pushy. He can be pretty overbearing. But it's because he genuinely has that desire to emotionally protect his partner, and because he can sense when things are wrong. I do think there could be some friction because Johnny is less likely than MJ to tell him to knock him off it terms he'll understand.
I also think there's kind of a slowburn protectiveness brewing with Johnny. Peter has a tendency to judge a book by its cover -- he makes snap judgments about people and he has to actually get to know them before he changes his opinion. He thinks MJ is a shallow party girl at first. He thinks Johnny is an airheaded show off in the early days. So even if he's gotten past that impression platonically, I think he still has preconceptions about Johnny that being in a romantic relationship would shatter in a million pieces with a hammer. Like, the assumption that Johnny enjoys all the attention he gets it, or that it's easy to a certain extent being Johnny with all his fame. Give it like half a month of a romantic relationship and Peter's going to try to fight Johnny's canonically terrible agent.
But aside from Peter being proactive and aggressive when it comes to being protective in public against threats either real or perceived, I think in private he's softer about it. Like I said, I think he's very emotionally protective. When it's just them, alone, he wants Johnny to feel safe and secure with him. So I think there the protectiveness manifests physically also, but less like a guard dog. An arm around the shoulders, sitting close together, kissing -- Peter's very into physical intimacy, and I think he would catch on pretty quick that it makes Johnny feel secure.
