Chapter Text
Seasons constantly change. Personalities change too. Through The 100, we've seen Abby and Marcus go from feeling wintery and bitter toward each other, to the burning summer love that we currently see them in.
The ark didn't fall to Earth during the winter, but Kane and Abby were bitter and cold to each other. They may have respected each other, but their full appreciation would not begin to blossom until mid s2. "breaking the law to keep you from becoming chancellor" was a winter flurry on an already cold relationship.
Their relationship didn't immediately get better overnight, and much like the seasons, there was a gradual change. After their fall to the ground, their temperaments became warmer toward each other, relating to a fall night when it's chilly, but you feel more warmth than a winter night. "I was afraid I wouldn't see you again.", "I had those fears myself". Abby begins to appreciate Marcus as someone who is willing to hold the burden of humanity if it keeps them alive, while Marcus is adapting Abby's "should we even survive" mentality.
Season 3 brings us to spring, and can be seen as the season where Kabby "springs" into action. their love is sprouting, and will not be fully admired until s4, but the blocks are beginning to be built. they work together to make each other and themselves better, much like how the sun and rain work together to bring beautiful life to plants. “I can't do this again” can be seen as a miracle grow placed on plants to expedite the growth process. Until this moment, each of them had feelings, but neither had expressed them in such a forward manner. Their relationship continues to grow from here, and the relief they feel at reuniting is overwhelming.
Season 4 is the season that Abby and Kane finally consider themselves “a couple” and they spend a few great nights in Polis. This is when their love is burning the brightest, and the world seems the most at peace for them. The summer is a time of feeling hot, and feeling free, which is how Kabby felt in Polis. They may have been separated, but their return to each other was full of love and concern for the other.