Peter Parker remembered in his first year as Spider-Man he had been drawn to Gotham for a plot by the Kingpin and wasn't exactly given a warm welcome by the infamous nocturnal vigilante known as the Batman who from the stories never approved of other more colourful superheroes intruding on Gotham. He got on more with his young sidekick Robin the Boy Wonder and had become good friends with his true identity of Dick Grayson (another young hero his age who had a sense of humour which Peter didn't think was possible when his mentor was Batman). When his group the Teen Titans were formed and operated in New York, he was welcomed with them.
Then came the young retreating alien princess Koriand'r which she had said translated to Starfire which became her superhero codename as she had joined them. The other Titans knew that even after she had kiss Dick to absorb the English language (an ability of her species the Tamarans). They had become closer and feelings towards each other grew to them dating.
Peter was disappointed with himself for basically breaking the bro code rule by crushing on his best friend's girlfriend but it was so hard not to; not only was she a fiery redhead who had 'girl next door' beauty but she was always so nice, so bubbly and overwhelming with positivity that it was overwhelming. He supported the couple as they had became older and the Teen Titans became just the Titans.
Robin ended up ditching the Robin codename to become Nightwing and though Kory with her Earth nickname stayed the same with her kindness and positivity, she grew into becoming drop dead gorgeous with a model like figure. Seriously a photoshoot with her and Wonder Woman herself would be the best thing ever (Wonder Girl Donna Troy liked to tease Peter when she had found out that he had a fanboy crush on her sister Diana when he was younger). It came ahead when the couple took Peter aside and admitted that they knew that he was in love with Kory with Dick saying that it was obvious and that he appreciated him not trying to get in the way.
Peter shut down before he could try and deny it when Kory asked if he wanted to join Dick in dating her with Dick nodding his head showing that he would be alright with it. Then the two best friends were dating their teammate with their friends and loved ones accepting the polyamorous relationship.
Kory was the best girlfriend you could ask for as everyone could see though in their private time and roleplay, she was more than happy to get into her parts:
When she was in control the two of them in man thongs (while admitting that they both looked good, Peter wouldn't be able to deny the butt that Dick had was something to be envied), Kory in her revealing bra and thong was able to walk towards them as befitting royalty. Peter allowed himself to act like a good butt kisser though Dick being the mouthier of them liked to make some remarks with Kory saying to teach him his place. Like pulling Peter into a deep kiss while making Dick.
They would also had sparring as if they were gladiators fighting for the queen's favour with Kory sitting down on a chair as if like a throne. All the training from Batman himself along with his years of experience was not something to be disregarded but Peter had years of fighting as well along with his Spider powers making him the victor more times than not. Kory would come closer to Peter flirtingly and looking down as if Dick being the loser meant that he was nothing more than dirt, Kory was such a good actress she would kill at the awards ceremonies if she pursued it as a professional career.
Plus with Kory sitting on the bed they would take it in turns with kissing her boots while the other would sit on her lap making out afterward she would bring them both in her arms as she lied down and giggled as her roleplay would act and the smiling sweet true Kory would show herself. She asked if they wanted to team up against her as they both kissed her cheeks with her giggling in response.
They had discussed plans for the future with Dick proposing with Peter as the best man but the three would know that all but officially Kory would be marrying all 3 of them and Kory wanted the possibility of them having a marriage ceremony on Tamaran as well as multiple partners being married was perfectly legal.
"So the whole of your family could see your little male harem?" Peter joked as Kory though about wishing that she was able to bare both of their children at once.
Despite multi shipping my favourite superhero Spider-Man, I admit that I am reluctant to ship him with Starfire as I am other heroines since DickKory is basically a huge OTP for me.
If you have any plot ideas or interaction ideas for a possible multi chapter Peter X Diana story then I am welcome to hear them please via PM with full credit given to ideas that I end up using.