Are cross-over ships accepted here too? Because boy do I have one.
See, Peter's thing is that he constantly wrestles with his sense of responsibility and his massive guilt complex. He wants someone to accept him for who he is, Spider-Powers, nerdiness, and all.
At times, depending on the writer, MJ can barely keep it together regarding Peter's "Spider-Man"ing putting him in constant danger, and until they got hitched, it was a source of constant drama between the two.
With Felicia Hardy, AKA the Black Cat, you had someone who loved Spider-Man, but not the man behind Spider-Man.
Because of this, Peter feels guilty, because if there's even the slightest chance of it being his fault, then it MUST be his fault... and it becomes a mess.
Enter Felicia, the catwoman Darkstalker. Someone who is the closest thing to a living ray of sunshine there is. Well, next to Pyron, anyway. She's someone who loves life, and loves to bring joy to others through her various entertainment-related talents. Being a Darkstalker, she also knows what it's like to be unfairly judged for preconceptions about what you are. Also, while she is literally the kindest Darkstalker ever, she will not hesitate to shred you into ribbons if you hurt those she cares about.
So right away you have someone who won't take Peter's constant self deprecation lying down, someone who can empathize with his struggles as a superpowered hero mistrusted by the people despite all the good he does for them, and will gladly fight for him, if not by his side.
It helps that they're both into kinky stuff, such as web-bondage in Peter's case, and in Felicia's, it's cosplay. You'd be fucking retarded to pass up a cute catgirl who loves you unconditionally and is probably willing to do some kinky shit with you.
What sucks is that there's so little content for the pairing that it's borderline criminal, and I lack both the talent and funds to help make more content.