When Nightcrawler decided to take up the mantle of Spider-Man, it was largely so that he could continue fighting back against the likes of Orchis without being relegated to the shadows. Besides the most obvious reasons for Nightcrawler's new mantle, there was also the underpinning hope that he could also smooth over some of the tensions between humanity and mutantkind. Now, those efforts have introduced a more romantic tension between himself and his latest foe, and it could make a huge difference in the battles to come.
Source:https://www.cbr.com/uncanny-spider-man-silver-sable-relationship-marvel/