One of the most iconic and dramatic power couples in the Marvel Universe is Scott Summers and Jean Grey, also known as Cyclops and Marvel Girl of the X-Men. Few pairings have had such a tumultuous history; Scott and Jean met back when they were both still teenagers having formed the original X-Men team alongside Angel, Beast, and Iceman. As they grew and matured their feelings for one another matured as well which led to them falling in love with one another. However, during a massive battle with Magneto in the heart of a volcano, both Scott and Jean thought the other died in the climax of the explosive battle. While Jean and Beast left the volcano and were rescued, Scott and the rest of the X-Men were lost in the Savage Land.
Scott and the X-Men eventually leave the Savage Land while Jean lives in Scotland with Moira MacTaggert, a geneticist and friend of the X-Men. In 1979's Uncanny X-Men #118 by Chris Claremont and John Byrne, the X-Men go to Japan to help the mutant hero Sunfire fight the tyrannical weapons manufacturer Moses Magnum. It was there that Scott met Colleen Wing, the cousin of Sunfire. Colleen Wing had been a common supporting character in Iron Fist and Luke Cage back in the late '70s, and she had a major role in two series that aired on Netflix, Iron Fist and The Defenders.
Colleen piqued an interest in Scott and began to flirt with him, hoping for the prospect of becoming a couple. In Uncanny X-Men #122 by Chris Claremont and John Byrne, the two went out on a date to a small ice cream shop and shared a soda. At the end of their day together Colleen slips Scott a piece of paper containing a note, a key to her apartment, and her address. As badly as Colleen wanted Scott to become interested in her, though, they never got together. Within the Marvel Universe, the reason for this, to put it bluntly, was that Colleen was a stepping stone for Scott. The X-Men leader never had the intention of mistreating her, but from a mental and emotional perspective, Colleen was a necessary step for Cyclops to heal and grow.
Scott was still processing the fact that Jean had died (as he still believed she had.) He was in shock over his lack of emotion over her supposed death. That alone was enough to suggest he was not in the right state of mind to enter a new relationship. Colleen found Scott to be good person, a strong leader, and a good friend, albeit a stuffy one at first. She saw the good in him, but also the pain and sorrow that he struggled to contain. Had the two of them dated it is very likely they would have had a wonderful and caring relationship with one another. Colleen would have helped Scott unwind and come to terms with the angst that burdened him and Scott would have been a loyal and strong partner for Colleen.
It was almost immediately after Colleen's flirting with Scott that he learned that Jean was still alive which put a definitive end to any chance of the two getting together as a couple. It would have been an interesting relationship to say the least.
The possibilities of how the future of the X-Men and the Marvel Universe itself would have changed without Scott returning to Jean are limitless. For what it's worth, though, it's still nice to know that Colleen wasn't dragged into any further X adventures and mishaps.