I have this headcanon of sorts that, following the merging of the Spiderverse and Equestria, all of Spidey’s love interests wound up leaving him for a superior pony girl. Black Cat started dating/stealing from/being teased by Rarity, Gwen Stacy was revived and given a place to rest by Twilight Sparkle, Venom gave up his long burning flame for Spidey and fused with Fizzle, Mary Jane hitting the real jackpot by meeting Sunset, etc. Then Mephisto shows up, reveals that by Peter giving him his marriage he also gave Mephisto a stake in the marital bliss, and with Peter newly single he and Mephisto are now bride and groom.