I actually don't find the "Don't look at my face!" aspect of it that creepy. Or at least the least problematic part of it. Since I always thought Black Cat and Spider-Man had a sexual relationship back in the old days it's kind of reasonable to assume that they could have had a similar "don't look at my face!" arrangement back then. I don't think that means they dehumanized or infantile-ized each other. To be crude, I think you can be intimate with another person if they're wearing a gimp mask.
That being said, this is yet another bit of evidence of how everyone in Peter's life being brainborked and having their characterization regressed makes shittier -- and not new types of -- stories. Instead of Peter having sex with an old flame it's now Peter having sex with a crazy lady who thinks seeing his real face deserves an "eww," which sucks. And it's another example of how Marvel continues to really mess up constantly when it comes to keeping Black Cat's character any level of consistent.
Felicia and Peter's relationship being characterized as not "grown up" also sucks.